Server IRC. Perche'?

Molti si chiederanno perché proprio un server IRC (quelli usati comunemente per chattare)... la spiegazione è semplice: il controllo. Per questi "cracker", avere a disposizione migliaia di router è inutile se non li posso controllare (o aggiornare) in modo univoco e veloce. Difatti la diffusione di questo "pacchetto" (passatemi il termine) è automatica. Quello che manca agli hacker è un modo per essere notificati delle nuove vittime e per controllare questi router, senza mettere a rischio la loro privacy e senza perdere troppo tempo. E il protocollo IRC è perfetto per questo scopo. Appena infettato, infatti, il programma si collega a questo server IRC, dando la possibilità ai cracker di mandare loro dei comandi. Sembra ovvio quindi che il server IRC girerà su qualche loro server, in modo da non poter essere loggati e/o bloccati. Sono pure entrato in uno di questi IRC Server, ma naturalmente i canali erano nascosti, e il funzionamento è predisposto in modo tale che curiosi come me trovino non poche difficoltà.

Ma perché tutto questo?

Molti si chiederanno del perché i cracker si sono presi questo disturbo. Posso rassicurare i lettori che (almeno nel mio caso) nessuno ha cercato di sniffare il traffico, quindi almeno la privacy è al sicuro (fortuna?). In questo momento mi vengono altri due usi comuni  per una rete di zombie router come questa:

• Un attacco del tipo DDoS (Distributed Denail of Service), ovvero reindirizzare tutti questi router per generare traffico/richieste verso un unico IP, in modo da rendere inaccessibile un determinato servizio (siti, computer, forum e chi più ne ha più ne metta). Avvolte queste reti vengono pure subaffittate per compiere questi lavoretti sporchi, rendendo bei soldi agli affittuari.
• Guadagnare con i servizi di "click & pay": immaginate 10000 computer che cliccano su un "banner"... il guadagno (anche se di pochi centesimi per click) crescerà nel giro di poche settimane. E la presenza di tanti IP non insospettirà i malcapitati gestori di questo genere di pubblicità, che non potranno neanche alzare obiezioni.

Naturalmente queste due sono solo supposizione, avendo difatto staccato subito il router dalla linea telefonica appena infettato, evitando di far infettare altri PC. Ho lasciato alcuni tecnicismi e altre prove (alcune  non mi hanno portato a niente) fuori da questo articolo, anche per non favorire script kiddies in erba :).

Contromisure

Questi programmi sono in grado di sfruttare le vulnerabilità dei router più comuni. Quindi l'unico modo per non diventare a propria volta delle vittime, è quello di aggiornare il firmware dei vostri dispositivi il più spesso possibile. Altri buoni consigli sono:

1. Cambiare la password di default del router.
2. Assicurarsi che il vostro router (o meglio la pagina di configurazione e i servizi telnet) siano accessibili solo dalla Lan interna e non dall'esterno.

Per come aggiornare il firmware e cambiare la password di default, fate riferimento al manuale del vostro router. Per verificare che il vostro router non sia accessibile dall'esterno, seguite i seguenti passi:

• Collegatevi al sito http://www.t1shopper.com/tools/port-scanner/
• Selezionate la spunta in corrispondenza di Telnet e Http (porta 23 e 80). Se volete potete selezionare anche le altre.
• Se qualcuna di queste porte risulta Open, allora dovete correre ai ripari: facendo riferimento al manuale del router dovete chiudere queste porte in modo che siano accessibili solo dalla LAN.

Se passate indenni questi test (e aggiornate costantemente il vostro firmware appena disponibile uno nuovo) dovreste stare tranquilli...
almeno per questi tipi di attacchi...
almeno finché qualcuno non scoprirà una nuova vulnerabilità del vostro router!
Alla fine, la prima regola della sicurezza informatica e che non si è mai al sicuro al 100 per 100.

So ... my new toys; Presenting the  DLink's DIR-655 wireless router, and DSL-520B ADSL modem/router.

I switched off the routing networking/facilities of the 520B by making it work in Bridged mode. This hereby relegated it to merely functioning as a modem. All the hard work is being done by the DIR-655, including dialing in to Streamyx, DHCP, wireless routing, etc. The process was pretty much straight forward:

On the DLink 520B, the important steps were:

1.  Choose Connection Type to be Bridging;

2. Encapsulation Mode to be set as VC/MUX; (this is the part that gave me the most trouble. The default setting for Encapsulation in Bridged mode was LLC/Snap-Bridging. );

3. All of the other crap such as Firewall, QOS, etc are turned off. And no, the Streamyx username/password is not set in the modem.

The above steps basically turns the DSL-520B into a modem-only mode. The Statistics page shows that I am connected to the Streamyx Line, but I am not yet logged in.

Once I connect the 520B to the DIR-655 via the CAT-5 cable, everything was pretty much the same as setting up a normal router on the DIR-655. My Streamyx username/password goes into the DIR-655, as well as turning on the DHCP, setting up the MAC Address access, etc.

All in all, it was a painless process and am very satisfied with the results. Of course, I am very unhappy with the fact I am only getting 400-600K on my 1M service subscription, but I've accepted a long time ago that Streamyx Sucks where service fulfillment is concerned.

I have not the need to reset either (apart from the initial upgrade-firmware-to-the-latest routine) ever since I finalised the settings for each. No degradation of performance (asides when Streamyx goes wonky) during my "1-month-marathon-no-switching-off" Test, and it just works!! My hottie neighbors are happy they can P2P and share files, I am happy all of my notebooks and PC are interconnected, my online-gaming sessions on Unreal Tournament or Steam is a breeze,  etc.

Did I mentioned earlier that I am one happy geek??!!

Anyways, my configuration is slightly pricey - but it was bought before the infamous Petrol Price Hike in Malaysia so yeah, whatever. If I had to buy it now .... that's a diffferent story I guess.

After coming home with the router, I was easily able to configure the router to connect using DHCP. However, after some time, we (family) began noticing the router would often disconnect our computers, yet still show as being connected in the wireless network icon of the system tray. Very weird... so, the solution was to just repair the connection and we would be all set.

Then we started noticing that after some idle time, the connection drop again, and we would have to repair. Other times the connection would randomly drop while on Ventrilo. Other times, the signal strength would fluctuate wildly, only to ultimately drop. Not fun...

We both have pretty old Linksys USB Adapters (WUSB54G) so updating those drivers were not an option.  However, we never had any connectivity issues with these adapters before using a Linksys WRT54G router running the DD-WRT firmware.

To troubleshoot the issue a bit, I logged into the DSL modem to look at the configuration. The modem was set to do PPPoE authentification with the option of "Connecting on Demand" after 20 minutes of idle time!!! Whoa! I promptly changed the modem configuration and selected an option to allow a computer to handle the PPPoE authentification.

I then reconfigured the DIR-655 to do PPPoE authentification and entered my username and password and made sure I checked the option to always keep the connection. Things seemed ok, for a bit...

The next night, our MMO gaming guild had a meeting and about 20 minutes into the meeting, I get disconnected! My wife is still online and connected with no issues. Again, I have to repair the connection. Roughly 10 mins later, my wife gets disconnected and must repair the connection. Ughh!

After reading pages and pages of issues similar to my own regarding the DIR-655 all over the interweb, I decide it's time to just return the router and go back to my trusted Linksys brand.

Today, I come home with a Linksys WRT610N router, configure the wireless settings, get the computer connected wireless, only to notice the signal strength on my wife's computer drastically fluctuates.  This cannot be, her computer is less than 20 feet away from the router in a different room.

So, after noticing the 2.4G channel is set to auto (which usually means 1 or 11), I decide to change it to 6. No real rhyme or reason, just picked a number. Still.. the signal fluctuates. I then download NetStumbler to try and get a decent profile of the wireless networks in my area. LO AND BEHOLD, everybody and their brother set their wireless channel to 6!  I promptly change it to one of the numbers not in use and whalaa, it's all good in the hood. Both computers are connected with very strong signal strengths!

I am keeping my fingers crossed in hopes that our wireless connectivity issues will be gone. We have roughly 5 days left before the Warhammer Online Early Headstart opens up!

I ended up leaving Mr. Ngo a voice mail (is he ever in, when I call him directly?) expressing my dissatisfaction that I was not mailed a check as he had promised. I inform him that I will promptly be trying to reach his supervisor to complain further.

I call the customer support line again, trying to get in touch with a customer support supervisor. After about 8 minutes of hold, I reach a low-level customer support representative. I immediately give her my most recent case number and ask to be connected with a supervisor. After a total of 35 minutes on hold, I hang up in the interest of trying to save cell phone minutes. I'm hoping that tomorrow will bring me more luck.

Let me preface this with the fact that I had previously been a big fan of D-Link. In the past, I had used D-Link routers. When custom-building PCs (back in the day before motherboards had onboard Ethernet), I typically used D-Link network cards. So going into this, D-Link was one of the more reputable network peripheral manufacturers in my mind. Oh, how little this was to last.

My print server of about 5 years (a Hawking HPS1U) was on its last legs. Although this had lasted me well, it was sputtering about and overheating seemingly every other day. I finally decided that it was time to lay this one out to pasture and find a replacement. After a lot of online research, I decided that the D-Link DPR 1260 would be a worthy replacement. The features that attracted me to this unit were:

• Wireless capability - after about 5 years of languishing with wired print servers, I thought it was about time to move onto the wireless age
• Support for multi-function printers - I had a HP PSC2110xi that I didn't feel like giving up any time soon, so when I read that the DPR 1260 could also share scan capabilities, my interests were definitely perked.
• Mac support - It's no secret that I'm a fan of Apple products (in retrospect, I should have simply bought an Apple Airport Extreme), so I of course wanted something that would work easily with my MacBook. Of course, the actual Mac support was relatively undocumented, but I had read a few articles online of enabling LPR/LPD support for the DPR 1260
• Low price - With some coupons and some specials that Circuit City was offering, I could pick up this baby for about $40, when at the time, most retailers were offering it for about $80 to $100!

And with that, I set off for Circuit City. For a grand total of $42.39, I had purchased the D-Link DPR 1260. By the evening, I had it set up in my apartment. Like I said, the Mac documentation was next to non-existent, but with my computer know-how and a few online articles, I had this DPR 1260 working with my Windows desktop, my MacBook, and my fiancee's Windows desktop and laptop computers. Everything seemed to go smoothly. For a while, I was even singing its praises...that is until the shit hit the fan!

The previous day, my print server seemed to stop working. My MacBook couldn't see it, none of the Windows computers seemed to be able to talk to it. It wasn't being seen as a UPNP device, and on my router's management screen, it wasn't listed as one of the machines on the local network. At close inspection, it even looked like that possibly one of its USB ports had malfunctioned, as it didn't even register that my printer was plugged into it. I tried every trick I knew...power cycling, depressing the Reset button in the back, restarting UPNP services on each of the Windows computers...everything. Since the print server was still under its 1-year warranty, I called D-Link's customer service to see if they could diagnose it over the phone. After waiting on hold for a good 10 minutes or so, a technical support representative pretty much walked me through the same steps I had already tried. They did offer me one additional step that I hadn't thought of...plugging the print server directly into one of my computers via Ethernet to see if I could access the web administration page directly. The technical support then deemed that my print server had to be returned to D-Link so they could repair the unit directly. I was assigned a case number (ALR399506313), and they sent me instructions on getting a Return Merchandise Authorization (RMA) number so that I could ship the unit back. The instructions involved going to the RMA website (http://rma.dlink.com) to register the product to be shipped back and to get an RMA number.

While going through the RMA website, I was a bit appalled to learn that I would have to pay for shipping my dead DPR 1260. I called their customer service phone number (1-800-326-1688) to complain about this, and the most they could offer me was that it was "standard company policy." I begrudgingly paid $11.94 for UPS to ship the defective DPR 1260 back to D-Link.

It took a while, but I finally received a replacement DPR- 1260. I quickly attempted to hook it up to my network. But was met with disappointing results. Had they simply shipped me back my defective unit without doing a thing to it? This unit had exactly the same symptoms as my previous unit. As I looked more carefully, I noticed that this was not my previous unit, as it had a different MAC address. Enclosed with the unit was a receipt from a Circuit City in Long Beach, CA. It looked as if they had simply taken a defective unit that someone in Long Beach, CA and sent back and sent it on to me.

I called D-Link once again to complain. Technical support walked me through the same steps...power cycling, ping the supposed address, depress reset button, plugging the unit directly into a computer...all the same steps that I had gone through on April 27. Once again, they assigned me a case number (PTS399537082) and had me go through the RMA process. But this time, I insisted there was no way I would pay again for shipping. The representative on the phone (Alan) gave me a new phone number to call regarding the RMA process. When I called this new phone number. I told the representative exactly what Alan told me to say, "I am requesting a call tag." Instead, I was met by someone (Jon Claud) who insisted on walking me through the technical support process yet again. I admittedly lost my temper and ended up shouting at the guy that this was the exact same thing Alan had me do. Why the hell did I need someone to run me through the exact same process only to issue me yet another case number (DLK399538409)?! Apparently, within the D-Link organization, only case numbers that begin with DLK can be approved for shipping without the customer paying. With this, I was sent a UPS label via email a few days later so that I could ship the second DPR 1260 back.

I was out of town this day and spending some relaxing time with my fiancee when Jon Claud (I was able to speak with him much more calmly this time) called me back. He said that he had received my unit (considering the time span between when I had shipped the previous unit and this call, he must have meant my original unit), and that he would inherently assign the DPR 1260 a different static IP address. I agreed, and hoped that this would solve all of my problems.

I receive an email saying that they had shipped me a replacement product.

I receive another unit, and once again, this one appears to be defective. The only marginal improvement was that when this new one was connected to my network, I could successfully ping the print server from my MacBook (but not from any of my Windows computers). Call to D-Link...same process...power cycle, reset button, ping IP address, plug directly into Windows computer...all the same thing over again. Once again, they assign me a case ID (ALR399557460) to have it shipped back. I asked if the technical support representative (Mike) could somehow just go ahead and assign me a DLK case ID, having learned about the RMA/Case ID procedure from before. No dice. He recited the same RMA procedure, and gave me the same RMA phone number as before. This time, when I called the RMA phone number, I first spoke with a gentleman name Robert, who then had me speak to his supervisor Michael Wang. Ultimately, I was given case ID DLK399557692, and I start patiently waiting for another UPS call tag.

Something's holding up my receipt of a UPS call tag. I call customer support (originally on May 23, 2008, but did not receive a return phone call until today). I speak with Blake Baston, who assures me that I will receive a UPS call tag within the next few days.

Still no UPS call tag. I call Mr. Baston directly (he gave me his extension last call), and end up leaving a voice mail.

Still no UPS call tag. I call again, asking to speak with someone else other than Mr. Baston, since he has not returned any of my calls. I end up speaking with Darren, who says he has forwarded the concern on to his supervisor, and that I can expect the call tag within a couple days.

I receive the following email from Van Ngo (apparent D-Link Customer Service supervisor/manager:


From: [email address hidden]
Subject: Re: Fw: CT request - Randy Chang; DLK399557692
Date: June 6, 2008 1:26:36 PM EDT
To: [email address hidden]

Randy,

Looking over the case, the print server does not seem like it is compatible with your printer. Would you like ot process a refund or perhaps swap it for a difference model? Please let me know. Thanks

In response, I quickly send him the following email:


From: [email address hidden]
Subject: Re: CT request - Randy Chang; DLK399557692
Date: June 6, 2008 4:48:28 PM EDT
To: [email address hidden]

Mr. Ngo

Given the choices, I would rather have a refund. Please let me know what will be involved in this process.

-Randy Chang

I receive an email from D-Link's RMA department telling me that I have been assigned an RMA number and asks that I ship back the defective product. Isn't this what I've been trying to do all along?!? I reply back to the email asking if I will receive a UPS call tag, as given that this is the third defective product (counting the original), and that I refuse to pay shipping.

I receive an email from Van Ngo in response to my RMA email. He simply states, "Yes." That was it?! I was a little appalled that he did not even acknowledge receipt of my previous email saying that I would like a refund. I felt like he should have at the very least shot me an email saying something like, "We're working on that refund now." A little concerned, I write him the following email:


From: [email address hidden]
Subject: Re: CT request - Randy Chang; DLK399557692
Date: June 10, 2008 4:48:28 PM EDT
To: [email address hidden]

Mr. Ngo

I just wanted to follow up and make sure you had received my request for a refund on this case. Please let me know what the status of this is and if you need any additional information from me to speed this up. Thanks!

-Randy Chang

Finally, later, in the day, I receive the UPS call tag.

I receive an email saying that they have received the defective DPR 1260 that I sent back.

A little concerned that I still haven't heard anything from Van Ngo regarding the status of the refund, I shoot him another email:


From: [email address hidden]
Subject: Re: CT request - Randy Chang; DLK399557692
Date: June 24, 2008 7:47:05 PM EDT
To: [email address hidden]

Mr. Ngo

It's been a while since I had heard from you about the refund (reference #DLK399557692). I wanted to find out the status of the refund and an ETA on the refund. Thanks!

-Randy Chang

He sends me back with the following:


From: [email address hidden]
Subject: Re: CT request - Randy Chang; DLK399557692
Date: June 24, 2008 7:56:18 PM EDT
To: [email address hidden]

Randy,

From my system notes, I believe a proof of purchase was still needed correct?

Van Ngo

I have to admit this was one thing he could kind of ding me on. After a few months of the print server seeming to work just fine, I had gotten rid of the original receipt. I did, however, still have my credit card statement that had this purchase on, so I sent Mr. Ngo a copy of this. If this wouldn't suffice as proof of purchase, he would at least have the decency to inform me of this, wouldn't he?

Still, I was a bit peeved that almost 2 weeks had elapsed since our last contact, and he waited until I had initiated another contact before he told me that there was something missing. If this were a responsible and responsive customer service department, wouldn't you think that they would at least inform me beforehand that this little piece of information was missing?

Once again, weeks go by without any word from Mr. Ngo or D-Link about the status of my refund. I would have at least expected something along the lines of "We received the credit card statement. This did/did not suffice as proof of purchase." So, once again, I send Mr. Ngo yet another email:


From: [email address hidden]
Subject: Re: CT request - Randy Chang; DLK399557692
Date: July 10, 2008 7:54:17 PM EDT
To: [email address hidden]

Hi Van Ngo

It's been a while since I heard from you last. Did the credit card statement suffice as proof of purchase? What is the status of the refund, and when can I expect to receive this? I will be moving in a couple weeks, so it is important to know when the refund will go through.

-Randy Chang

I received no response from him. The part about moving was not a lie. I was scheduled to move from Atlanta to Maryland at the end of July 2008.

Around this time, several things were starting to consume me. I was trying to complete some final projects for work before I was scheduled to leave, and of course I was starting to pack up for my impending move. Amidst all of this, I realized that I had still not received anything from Mr. Ngo or from D-Link. Given his general pattern of not communicating back, I decided to instead email D-Link's customer service department hoping someone from their ranks would see this and respond in some way or another.


From: [email address hidden]
Subject: ongoing technical and support problems
Date: July 21, 2008 1:02:11 PM EDT
To: customerservice@dlink.com

To whom it may concern:

Let me first state that I have been a longtime fan of D-Link products. Whenever I assemble a home-built PC, I use D-Link NICs, and I often recommend D-Link to others as well. I am also on my second D-Link router, as these have commonly served me very well in the past. However, my faith in D-Link has recently been shaken, and I am ready to take my business elsewhere.

I have had repeated trouble with your DPR-1260 print server. These problems started in April 2008, and despite several calls to your technical and support departments, the problem has not resolved. I originally purchased the print server at Circuit City in December 2007. It seemed to work fine within my home network (consisting of a D-Link DIY 655 router, an HP PSC 2110xi multifunction printer, and several Windows-based and Mac-based laptops and desktops) up until April 2008. At this point, the print server refused to be seen on my network as a UPNP device, and I was unable to access the print server's web configuration page. Given that this print server supposedly has a 1-year warranty, I called your technical support department to hopefully resolve the issue. I went through a series of case numbers, and there seemed to be a repeating cycle: through phone diagnoses, my print server was deemed to be malfunctioning, and I would send the print server back to you. Annoyingly, each time a replacement unit was sent to me, the replacement unit seemed to be malfunctioning as well. Based on my records, I have mailed back 3 units to you. (By the way, I find it incredibly disappointing that the standard RMA process involves the customer paying to return a defective unit; it is as if you are penalizing the customer even though it is your productive that is defective.) Based on my records, I have also had the following reference ID's related to this problem: ALR399506313, PTS399537082, DLK399538409, ALR399557460, DLK399557692. My last contact was through email with someone named Van Ngo, who deemed that the most appropriate remediation would be to offer me a refund. However, my last contact with him was June 24, 2008. Despite repeated attempts to email him back, I have received no reply as to the status of my refund or even an ETA. I will soon be moving (within 2 weeks), which may complicate the refund process, but I still find it appalling that 4 months have elapsed, and this has not been resolved.

-Randy Chang

Of course, I received no immediate reply.

Finally with some downtime with the major bulk of the move done, I decided to try D-Link's customer service email again.


From: randykchang@gmail.com
Subject: problem not resolved after 5 months!!!!!!!
Date: August 10, 2008 8:53:30 PM EDT
To: customerservice@dlink.com

To whom it may concern:

Let me first state that I have been a longtime fan of D-Link products. Whenever I assemble a home-built PC, I use D-Link NICs, and I often recommend D-Link to others as well. I am also on my second D-Link router, as these have commonly served me very well in the past. However, my faith in D-Link has recently been shaken, and I am ready to take my business elsewhere.

I have had repeated trouble with your DPR-1260 print server. These problems started in April 2008, and despite several calls to your technical and support departments, the problem has not resolved. I originally purchased the print server at Circuit City in December 2007. It seemed to work fine within my home network (consisting of a D-Link DIY 655 router, an HP PSC 2110xi multifunction printer, and several Windows-based and Mac-based laptops and desktops) up until April 2008. At this point, the print server refused to be seen on my network as a UPNP device, and I was unable to access the print server's web configuration page. Given that this print server supposedly has a 1-year warranty, I called your technical support department to hopefully resolve the issue. I went through a series of case numbers, and there seemed to be a repeating cycle: through phone diagnoses, my print server was deemed to be malfunctioning, and I would send the print server back to you. Annoyingly, each time a replacement unit was sent to me, the replacement unit seemed to be malfunctioning as well. Based on my records, I have mailed back 3 units to you. (By the way, I find it incredibly disappointing that the standard RMA process involves the customer paying to return a defective unit; it is as if you are penalizing the customer even though it is your productive that is defective.) Based on my records, I have also had the following reference ID's related to this problem: ALR399506313, PTS399537082, DLK399538409, ALR399557460, DLK399557692. My last contact was through email with someone named Van Ngo, who deemed that the most appropriate remediation would be to offer me a refund. However, my last contact with him was June 24, 2008. Despite repeated attempts to email him back, I have received no reply as to the status of my refund or even an ETA. I have even attempted emailing your customer service department (dated July 21, 2008), with no reply.

Either I will be refunded my money in a timely manner, or I respectfully request that you send me a brand new print server (brand and model OF MY CHOOSING). I have been more than patient, but this patience is wearing thin.

-Randy Chang

As you can tell, this was a virtual copy and paste of my previous email with a few details changed here and there.

My patience has more than drained, so this time I call up their customer service so that I can talk to an actual human being. After waiting through an ungodly wait time, I speak to a young lady. When I give her my case ID, she has the gall to ask if I would like to use technical service to resolve my case. At this point, I don't even have a physical unit to diagnose. I said that I should speak directly to Mr. Van Ngo, as he would be the only person who would be able to resolve my case. I tell her that I'd rather not speak to Mr. Ngo, as he has historically not returned my calls or emailed in a timely fashion. She insists that Mr. Ngo is the only one who can address the case, yet he is out of the office. Despite my protests, she routes me to his voice mail. I end up leaving a fairly angry voicemail (though I amazingly was able to refrain from cursing) about the history of my case, and my disappointment that approximately 5 months have elapsed with no resolution to this case. I demand that he call me back by Monday August 18, 2008 (the next business) day, or else there would be hell to pay, and I'd simply lodge a personal complaint against him to his supervisor.

No call from Mr. Ngo.

To keep with my promise, I call D-Link's customer service. I finally hear a human voice after about 6 minutes of wait. I immediately demand to speak with a supervisor. The representative asks for my case ID. After I tell her, she says that she can route me to Van Ngo. At first, she insists that Van Ngo is the supervisor. I then insist on talking to someone above Mr. Ngo, but she seems ignorantely unaware of who that would be. Then, she verifies that Mr. Ngo is in!I wait on hold for what felt like another 3 minutes. Finally, I'm speaking with Mr. Ngo, a man who has earned a lot of ire in my eyes and ears.

He tells me that he was unable to process the refund because my credit card statement does not qualify as a valid form of proof of purchase. I'm wondering why he didn't tell me this when I initially submitted this. I'm also pretty livid at this point. He tells me that what he can do is give me a "rebate" of $40, as D-Link submits these "rebates" in increments of $20. When I hear the word "rebate" I get further upset, as to me, the word has a connotation of having to buy another product before I get anything of $40 value. I spout off that this experience has spurred me to never buy D-Link again, so how does he think I would be satisfied with this so-called rebate? He then explains that D-Link is basically giving me a $40 check. So why didn't he call it a "refund" in the first place? I then inform him that my mailing address has since changed due to the move. He asks that I email him the new address. I insist that he stay on the phone with me while I email the new address so that I can be sure that he has received it. While I'm mailing this off, I spout off on each of the inconveniences this whole ordeal has set me through...seemingly repetitive and incompetent customer/technical support, irresponsibly sending me DOA units, the ungodly time this has taken to resolve, the lack of communication, feeling penalized for the RMA process of paying to ship back D-Link's defective product...all of this comes spewing out of my mouth. All Mr. Ngo does is apologize and state that these are all company policies. I further state that for a company of D-Link's stature, I feel that their customer service department reflects a sense of irresponsibility. For a while, I probably sounded like a thesaurus, as I spout off words like appalling, deplorable, irresponsible, etc.

Now, I'm just waiting for the check to arrive. I also ask for Mr. Ngo's personal extension so that in case I do not receive the check by September 2, as promised, I can speak with him directly without having to be put on hold for 5 months.

มร.เดสมอนท์ โทห์ ผู้อำนวยการฝ่ายการตลาดของดีลิงค์ ได้กล่าวว่า “การสร้างสรรค์และแบ่งปันดิจิตอลคอนเทนต์จะไม่ใช่เรื่องยากอีกต่อไปสำหรับผู้ใช้เทคโนโลยี ยิ่งทุกวันนี้มีการใช้งานกล้องดิจิตอล เครื่องเล่นเพลง และโทรศัพท์กันอย่างแพร่หลาย สำหรับหน้าที่ของ DNS-313 จะช่วยให้ผู้บริโภคสามารถเข้าถึงความเพลิดเพลินของโลกดิจิตัลได้อย่างเต็มที่ ซึ่งจะช่วยให้ทุกคนสามารถแบ่งปัน จัดเก็บดิจิตัลคอนเทนต์และไฟล์ได้อย่างสะดวกและง่ายดาย”

ความสามารถในการเก็บรักษาและจัดเก็บข้อมูล

ด้วยความสามารถในการทำงานเป็นที่จัดเก็บข้อมูลบนระบบเครือข่ายหรือ Network Attached Storage (NAS) ผ่านทางกิกะบิตพอร์ตความเร็วสูง และเป็นสตอเรจโดยตรง หรือ Direct Attached Storage (DAS) ที่ผ่านทางการเชื่อมต่อยูเอสบี อุปกรณ์ DNS-313 ยังออกแบบมาให้ใช้งานร่วมกับฮาร์ดดิสก์ขนาด 3.5 นิ้ว แบบ SATA ซึ่งสามารถรองรับความจุฮาร์ดดิสก์ได้สูงถึง 1000 กิกะไบต์หรือมากกว่าได้ นอกจากนั้นผู้ใช้งานยังสามารถแบ่งปันและเข้าถึงไฟล์เอกสาร ข้อมูล และดิจิตัลมีเดียอื่นๆ เช่น เพลง ภาพถ่ายและวิดีโอร่วมกันได้อย่างง่ายดายภายในระบบเครือข่ายของบ้านหรือที่ทำงาน ยิ่งไปกว่านั้นภายในตัวเครื่องยังได้ติดตั้ง FTP เซิร์ฟเวอร์ เพื่อให้ผู้ใช้สามารถเข้าถึงไฟล์ข้อมูลผ่านทางอินเตอร์เน็ตได้ และเพื่อเพิ่มประสิทธิภาพของการรักษาความปลอดภัย DNS-313 ยังให้สิทธิ์ผู้ใช้ในการคอนฟิกกลุ่มผู้ใช้และกำหนดว่าจะอนุญาตให้ผู้ใช้กลุ่มนี้สามารถอ่านหรือทั้งอ่านและเขียนข้อมูลลงในไฟล์นั้นๆ ได้หรือไม่ วิธีนี้จะช่วยให้ทุกข้อมูลมีความปลอดภัยอยู่ได้ ด้วยการกำหนดสิทธิ์ที่ตัวผู้ใช้หรือกลุ่มผู้ใช้เท่านั้น

DNS-313 มาพร้อมด้วยซอฟท์แวร์ที่ช่วยในการสำรองข้อมูล ที่จะช่วยให้ผู้ใช้สามารถสำรองข้อมูลของตนเองจากคอมพิวเตอร์ได้โดยตรง เพิ่มความปลอดภัยให้กับข้อมูลจากผู้บุกรุกหรือไวรัสคอมพิวเตอร์ อีกทั้งยังสามารถกำหนดตารางการดาวน์โหลด ที่จะช่วยให้ผู้ใช้สามารถเลือกแฟ้มเอกสารที่ต้องการจากไฟล์ที่จัดเก็บไว้ในคอมพิวเตอร์โดยดาวน์โหลดผ่าน FTP หรือเว็บเซิร์ฟเวอร์ นอกจากนั้น DNS-313 ยังได้รับการออกแบบมาอย่างชาญฉลาดในด้านการใช้พลังงาน ที่จะช่วยประหยัดพลังไฟและช่วยถนอมการใช้งานของ
SATA ฮาร์ดดิสก์ อีกทั้งยังช่วยยืดอายุการใช้งานของฮาร์ดดิสก์ได้ในเวลาเดียวกันอีกด้วย

DNS-313 ไม่สร้างความยุ่งยากในการทำงานบนระบบปฏิบัติการใดให้กับคุณ เพราะสามารถใช้งานได้ทั้งบนระบบปฎิบัติการ Windows และ MAC

สตรีมดิจิตัลมีเดียคอนเทนต์ได้อย่างเต็มรูปแบบ

DNS-313 ได้ติดตั้งมีเดียเซิร์ฟเวอร์ UPnP AV ที่จะช่วยในการสตรีมดิจิตัลคอนเทนต์ให้กับเครื่องเล่นมีเดีย และยังรองรับซอฟท์แวร์ iTunes ที่ให้ผู้ใช้สามารถค้นหาและเล่นเพลงได้โดยตรง นอกจากนั้น DNS-313 ยังมีคุณสมบัติที่เพิ่มเติมมาเป็นพิเศษ คือ D-Link's Click'n Connect (DCC) ที่จะช่วยให้การติดตั้งทำได้อย่างง่ายดาย โดยได้ออกแบบให้ทำหน้าที่แนะนำการใช้งานแก่ผู้ใช้ที่ไม่มีความรู้ด้านเทคนิคมาก่อน สำหรับคุณสมบัติ D-Link's Easy Search Utility จะช่วยให้ผู้ใช้สามารถกำหนด DNS-313 บนระบบเครือข่ายและแม็พฮาร์ดไดร์ฟได้อย่างรวดเร็ว ซึ่งจะช่วยให้ง่ายต่อการค้นหาเครื่องพีซีที่ใช้งานต่อไป

ใน ฐานะประธานเจ้าหน้าที่บริหารและประธานสำนักงานใหญ่ มร.เธา จะเป็นผู้นำในการขับเคลื่อนธุรกิจของดีลิงค์ทั่วโลก โดยให้ความสำคัญกับการพัฒนาตลาดใหม่เป็นพิเศษ ในขณะเดียวกันก็ยังคงสานต่อเจตนารมณ์ของผู้ก่อตั้งคือ มร.เคน เคา ซึ่งมร.เธา จะทำหน้าที่เป็นผู้บริหารของดีลิงค์ อินเตอร์เนชันแนลด้วย

การ แต่งตั้งตำแหน่งใหม่นี้ มีขึ้นหลังจากการลาออกของมร.จอห์น ลี ประธานและประธานเจ้าหน้าที่บริหารคนปัจจุบัน รวมถึงมร.เจ.ซี. เหลียว ประธานคนปัจจุบัน ซึ่งมีผลอย่างเป็นทางการเมื่อวันที่ 1 กรกฎาคม 2551 ทั้งนี้มร.เหลียว เคยมีโอกาสได้ร่วมงานกับดีลิงค์ในส่วนของภาคพื้นยุโรปมาก่อนเป็นระยะเวลายาว นานถึง 12 ปี ก่อนที่จะมารับตำแหน่งประธานของดีลิงค์ คอร์ปอเรชันในปี 2546

" นับเป็นความโชคดีของเรา ที่สมาชิกที่มีความสามารถสูงอย่างมร.โทนี เธา ตกลงใจรับตำแหน่งนี้" มร.ลี ประธานของดีลิงค์คนปัจจุบันกล่าว "และด้วยประวัติการทำงานด้านการพัฒนาธุรกิจเครือข่ายที่ยาวนาน ประกอบกับความสามารถในการบริหารจัดการจะช่วยให้บริษัทมีความเจริญรุดหน้า และทำให้องค์กรบรรลุวัตถุประสงค์ในการก้าวไปสู่การเป็นผู้นำสูงสุดของแบรนด์ ด้านเครือข่าย"

จาก ที่ดีลิงค์เป็นที่รู้จักและยอมรับในฐานะผู้นำโซลูชันด้านเครือข่ายที่ใช้งาน ง่าย ปัจจุบันดีลิงค์ยังเป็นผู้นำระดับโลกที่ผลิตและส่งออกอุปกรณ์ Draft 802.11n Wi-Fi ซึ่งจากผลการวิจัยของ In-Stat ซึ่งเป็นหน่วยงานวิจัยด้านเทคโนโลยี Reed Business Information ของสหรัฐฯ ได้รายงานว่า ดีลิงค์ได้ส่งออกอุปกรณ์ของเทคโนโลยี Draft 802.11n เป็นจำนวนถึง 584,000 ชิ้นในไตรมาสที่ 4 ของปี 2550 ซึ่งคิดเป็น 33% ของสัดส่วนตลาดโลกโดยรวม

ใน ปีเดียวกัน ดีลิงค์ยังได้รับการจัดอันดับจาก Taiwan External Trade Development Council (TAITRA), BusinessNext และ Interbrand ให้อยู่ในลำดับที่ 6 ของแบรนด์สินค้าที่มีคุณภาพระดับโลก ซึ่งนับเป็นครั้งที่ 2 แล้วที่บริษัทได้รับการจัดอันดับ ทั้งนี้เพราะดีลิงค์เป็นแบรนด์คุณภาพ ที่สามารถสร้างยอดขายได้ถึง 347 ล้านดอลลาร์สหรัฐฯ และมีการเติบโตที่สูงถึง 40% เมื่อเทียบกับปี 2549 และมีรายได้รวมตลอดปี 2550 ที่ 1,012 ล้านดอลลาร์สหรัฐฯ

" นับแต่ได้รับการแต่งตั้งให้ดำรงตำแหน่งประธานกรรมการบริหารของดีลิงค์ อินเตอร์เนชันแนลเมื่อปี 2540 มร.โทนี ได้กลายเป็นผู้บริหารหลักของกลุ่มกรรมการบริหารของดีลิงค์ และด้วยความสามารถของเขา ทำให้เราประสบความสำเร็จเป็นอย่างยิ่งในกลุ่มตลาดใหม่ และการบริการลูกค้าในกลุ่มเอนเตอร์ไพรส์และ SME ขณะเดียวกันยังประสบผลสำเร็จในการสร้างความคุ้มค่าให้กับสินค้าและบริการ รวมถึงยังคงรั้งตำแหน่งผู้นำทางการตลาดไว้ได้อีกด้วย" มร.ลี กล่าวเสริม

ใน ฐานะประธานกรรมการบริหารของดีลิงค์ อินเตอร์เนชันแนล มร.เธา จะรับผิดชอบในการพัฒนาและการเติบโตของตลาดในภูมิภาคเอเซียแปซิฟิค, อเมริกาใต้, ตะวันออกกลาง และรัสเซีย ยิ่งไปกว่านั้นแล้ว เขายังจะรับผิดชอบการดูแลตลาดที่เกิดใหม่ในละตินอเมริกา, อัฟริกาใต้, ตะวันออกกลาง, รัสเซีย, อินเดีย และเวียดนาม และยังมีบทบาทสำคัญยิ่งในการสร้างอัตราการเติบโตรวมของดีลิงค์ อินเตอร์เนชันแนล ให้โตขึ้น 23% จาก 301 ล้านดอลลาร์สหรัฐฯ ในปี 2549 ให้เป็น 369 ล้านดอลลาร์สหรัฐฯ ในปี 2550

ก่อน ที่จะเข้าร่วมงานกับดีลิงค์ในปี 2540 มร.เธา เคยร่วมงานกับบริษัทไอบีเอ็ม เป็นระยะเวลานานเกือบ 8 ปี ในตำแหน่งผู้จัดการฝ่ายพัฒนาธุรกิจช่องทางการจัดจำหน่ายของภูมิภาคเอเชีย หลังจากนั้นจึงได้มาร่วมงานกับ Digital Equipment Corporation เป็นเวลา 3 ปีครึ่งดูแลด้านการบริหารจัดการช่องทาง SME และช่องทางการจัดจำหน่ายในภูมิภาคเอเชียแปซิฟิค มร.เธา สำเร็จการศึกษาระดับปริญญาตรี สาขาการจัดการอุตสาหกรรม จาก Ming-Chi Institute of Technology ประเทศไต้หวัน และปริญญาโทสาขาบริหารธุรกิจ จาก Illinois Institute of Technology มลรัฐชิคาโก สหรัฐอเมริกา

Prefazione

All'utente medio/basso poco importa di come e perché il suo computer funzioni: basta che faccia il suo compito. Ma mentre è normale per le persone installare l'antifurto sulla propria macchina, oppure conservare la proprio pistola in un posto sicuro, quando si tratta di informatica l'unica cosa che gli interessi è che vada sul momento. Non mi va di dilungarmi troppo sull'argomento di quanto sia importante conoscere almeno l'abc della sicurezza informatica, ma leggere questo articolo forse vi farà aprire gli occhi. In questa prima parte voglio fare un pò di precisazioni su i termini stra-usati dai giornalisti in maniera poco opportuna. Naturalmente sono considerazioni personali e sintetizzate in poche righe, nulla da prendere da oro colato visto c'è gente che ha scritto libri sull'argomento senza riuscire ad mettere tutti d'accordo.

Hacker: Se per voi l'Hacker è quello che sta dietro il computer per cercarvi di fregare la password del vostro account, vi state sbagliando. Nel gergo informatico (e non solo), viene indicato come colui che si ingegna per sopperire a problemi di natura informatica e non.  L'hacker è una persona etica, che difficilmente userà le sue conoscenze per recare danni e/o rubare informazioni o, ancora peggio, per lucrare infrangendo la legge. Non dico che non esistono persone che possono usare le loro conoscenze per i propri fini, ma questo esce fuori dall'etica che circonda queste persone. Per dividere le categorie, alcuni suddividono gli hacker in black hat (i cattivi) e i white hat (i buoni), ma la definizione è sempre troppo minimalistica. Ignoranza, luoghi comuni e altri fattori, fanno si che il divario tra i buoni e i cattivi sia minimale, nonostante la differenza sia enorme. Lo stesso Linus Torvalds si definisce "programmatore" se parla con i giornalisti, hacker se parla con gente competente, per evitare che la gente lo identifichi con un informatico con la benda sull'occhio. E allora i cattivi chi sono? ...

Cracker: solo coloro che usano le loro conoscenze per aggirare le difese ed eludere blocchi di software/sistemi informatici. Alcuni li identificano con i black hats, ma personalmente li vedo ad un gradino inferiore. E' come una zona di limbo tra i black hat e gli script kiddies...

Script Kiddies: sono coloro che utilizzano il codice, le scoperte e le informazioni derivati da altri per ottenere informazioni o aggirare sistemi. Molte volte non si preoccupano neanche di capire come una cosa funziona, ne tanto meno migliorarla. La scaricano, la usano e basta. Sono consoni definirsi "aquers" nelle irc chat o sugli amici su Msn.

L'attacco

Analizzando il log del mio router da un mese a questa parte, vedo continui tentativi di accesso sulla porta 23 (Telnet). Analizzando l'ip di provenienza, mi sono accorto che si trattava, per lo più, di router D-Link di ignari utenti: basta infatti inserire uno di questi ip nel proprio browser e uscirà la pagina di configurazione in router, quella pagina che di solito dovrebbe essere solo visibile all'interno della lan (da indirizzo come 192.168.0.1) e mai da remoto (con il vostro ip internet). Quindi colui o coloro che portavano avanti l'attacco si servivano sicuramente di una falla di sicurezza presente in questi router.
Quale falla? Difficile a dirsi. Perché i router sono un bel pò di tipi, e quindi credo che l'algoritmo usato dai crackers, in questo caso, faccia selezione a seconda del router trovato vulnerabile. Sicuramente interesserà delle vecchie falle nei firmware dei router, famosi in certi ambienti.

A questo punto che fare? Mi procuro un Dlink e faccio da vittima... tutto questo nella prossima parte dell'articolo...

Resumo do artigo anterior:

No artigo anterior, tentei apresentar os perguntas que devem ser feitas se você quiser montar sua própria rede, seja em casa, no escritório, ou na loja. Essas perguntas - sobre suas necessidades reais - ajudam definir uma estimativa dos custos e das dificuldades do projeto.

Neste artigo, apresentarei uma solução simples para permitir a conexão sem fios de dois computadores à Internet, compartilhando uma impressora, situação que deve cobrir 95% dos casos de redes em casa. Apresentarei junto uma opção com fios, mais barata porém limitando a possibilidade de mudar o local dos computadores.

Uma Solução Simples

Você tem:

• Uma conexão Internet com um provedor de Banda Larga (ADSL ou a Cabo)
• Um modem - comprado ou alugado com o provedor ou de outra fonte (funcionando com o provedor)
• Dois computadores relativamente recentes (2004 ou após) rodando Windows XP (Home ou Profissional)
• Opcionalmente, uma impressora conectada a um dos computadores (qualquer modelo)

Eventualmente, se você tiver uma simples conexão com modem comum (conexão lenta), você também tem a possibilidade de compartilhar essa conexão entre ambos computadores, mas eu recomendo fortemente a assinatura de uma conexão mais rápida.

Se você quiser uma rede sem fio, você precisará comprar um equipamento chamado roteador sem fio, e duas placas de rede sem fio. O custo aproximativo dessa configuração deve ficar entre R$400 e R$700, conforme meu artigo anterior. A diferença de preço depende da marca, da tecnologia e das funcionalidades avançadas dos equipamentos. Sugiro comprar equipamentos da mesma marca para evitar possíveis problemas e incompatibilidades futuros. Recomendo as seguintes marcas: Linksys, Trendnet, 3com e D-Link (nessa ordem).

Se você quiser uma rede com fios, você só precisará de um roteador comum, e 2 cabos de rede de tipo Cat5 (cabos de tipo Cat5E ou Cat6 também valem embora estejam mais caros e dispensáveis numa rede de casa). Essa solução não deve passar de R$300, embora lembro da limitação de mobilidade imposta pelo uso de cabos.

Segue um desenho recapitulativo de ambas soluções.

A diferença entre os dois esquemas é no modo como os computadores estão ligados ao roteador. Também no caso da solução com fio, é impossibilitado o uso de um smartphone ou PDA wireless como na solução sem fio - embora nem todo mundo possua um equipamento desses...

Também, não inclui um acessório bem útil para quem faz muitas ligações telefônicas interurbanas ou internacionais e quer economizar na conta de telefone. Este acessório se chama de adaptador VoIP (comunicações de voz via a Internet). Esta opção pode também estar integrada ao roteador. Veremos isso num outro artigo.

Agora, vamos entrar em assuntos menos teóricos: quais equipamentos, e como instalá-los.

Os equipamentos

Vou dividir essa secção em duas partes, conforme a solução escolhida. Acredito que haverá mais pessoas interessadas na solução sem fio, por sua simplicidade, no entanto recomendo ter a curiosidade de ler a parte sobre a solução com fios também, não só por curiosidade, mas também para entender melhor como tudo isso funciona...

a) Rede com fios

Costumo usar equipamentos Linksys, Trendnet, 3com e D-Link. Por isso recomendo escolher um roteador dessas marcas, com as seguintes caraterísticas:

• Roteador Banda-Larga
  Isto é: o roteador não precisa integrar um modem ADSL ou cabo - e até recomendo não comprar integrado - mas precisa ter a função de ROTEADOR. Não pode ser um SWITCH, e não pode ser um HUB. Também insisto no fato que ele deve ser roteador BANDA-LARGA, e não um roteador comum, que não teria as funcionalidades necessárias para estabelecer a conexão internet.
• De 4 até 8 portas (conexões de rede local ) Ethernet 10/100 Mbps
  4 portas devem satisfazer a maioria dos casos e deixar um pouco de espaço para 2 equipamentos adicionais. 8 portas é preferável se for para um escritório ou uma loja.
  A rede suportada deve ser 10/100 Mbps, mas qualquer modelo suportando 1 Gbps (10/100/1000 Mbps) funcionará também, embora representaria um luxo.
• O equipamento deve suportar o NAT/NAPT e port forwarding
• O roteador possui um firewall embutido, idealmente "SPI" (Stateful Packet Inspection, ou simplificando: análise dos dados para autorização das conexões)
• Configuração por página web

Eis uns modelos apropriados para nossa rede simples (para escritórios ou pequenas empresas, eu recomendarei outras funcionalidades num próximo post)

1. Linksys: BEFSR41 (4 portas) ou BEFSR81 (8 portas)
   
2. Trendnet: TW100-S4W1CA ou mais seguro: TW100-BRF114
   
3. 3com: 3CR858-91
   
4. D-Link: DIR-100 (4 portas)
   

Os computadores, recentes, devem ter uma conexão de rede na parte de trás (do lado dos conectores para periféricos USB):

Se não for o caso, você precisará de uma placa de rede Ethernet 10/100 de alguma marca acima ou eventualmente de marcas mais baratas (Encore,...), dependendo do nível de garantia que você procura... Se seu PC rodar o XP, tem grande chances que você possa pedir uma placa chamada de PCI, caso contrário você terá que ficar com uma placa ISA ou EISA mas sugiro logo o upgrade do computador, porque você está se metendo numa encrenca das boas e de qualquer modo seu computador já deve ter uns 10 anos e é hora de seguir com o progresso ;)

[Atualizado: 06-jul-2008]

Como mencionado mais cedo, você precisará também de 2 cabos de tipo Cat5, Cat5E ou Cat6 (o primeiro tipo é mais que suficiente). O tamanho desses cabos deverá ser suficiente para conectar cada computador ao roteador, e o roteador será conectado ao modem pelo cabo fornecido com o modem (pode vir um cabo também com o roteador), geralmente de 1,5m.

Uma atenção particular deve ser dada aos cabos de rede, que não devem ser entortados, dobrados ou esticados com força: esses cabos tem dentro 8 fios de diametro pequeno que não resistem muito bem a tensões exageradas. Pense no cabo de rede como num cabo de antena ou de TV: dobrou, ferrou.

Também, se você tiver que passar um cabo entre dois quartos, você deverá furar as paredes com uma broca de tamanho suficiente para passar juntamente o plugue, isto é: recomendo pelo mínimo uma broca de 12mm; faz um buraco meio feio, mas nada que um pouco de massa não melhore...

Na teoria, o cabo pode ter até 100m, o que dá conta de qualquer casa, apartamento ou pequeno escritório. Melhor prever uns metros a mais, porque não tem como fazer extensões desses cabos sem a ajuda de um equipamento adicional, chamado de hub...

Enfim, se o negócio dos cabos já lhe-parece uma possível dor de cabeça, sugiro logo optar pela solução sem fio ;)

[Fim atualização]

b) Rede sem fios

Neste caso de figura, precisaremos de um roteador sem fio e de dois adaptadores sem fio (ou mais se tiverem mais de 2 computadores na rede).

Seguem as caraterísticas do roteador (muitas são idênticas ao roteador comum)

• Roteador sem fio de banda-larga
• 802.11g/54 Mbps no mínimo
• 4 ou 8 portas Ethernet 10/100
• funcionalidades NAP/NAPT e port forwarding
• Firewall embutido, idealmente SPI
• Encriptação WPA (a encriptação WEP, embora muito comum, não é suficientemente segura)
• Filtragem de endereços MAC (embora a configuração dessa opção possa ser meio chata e muito restritiva, ela garante, junto com a encriptação, a melhor segurança possível de sua rede)

Aqui estão alguns modelos apropriados:

• Linksys: WRT54G
  
• Trendnet: TEW-432BRP
  
• 3com: 3CRWER100-75 (54Mbps) ou 3CRWER200-75 (54/108Mbps, proprietário)
  
• D-Link: DI-524
  

As caraterísticas das placas de rede sem fio (PCI) ou dos adaptadores sem fios (USB) seguem:

• 802.11g/54 Mbps no mínimo
• Encriptação WPA
• Compatível com o Windows XP

Seguem modelos do comércio:

• Linksys: WMP54G (PCI) ou WUSB54G (USB) ou WUSB54GC (USB, tipo pendrive)
  
• Trendnet: TEW-423PI (PCI) ou TEW-424UB (USB)
  
• 3com: 3CRDAG675B (PCI) ou 3CRUSB20075 (USB,108Mbps) ou 3CRUSB10075 (USB,54Mbps)
  
• D-Link: DWL-G520 (PCI) ou DWL-G132 (USB)
  

Resumindo

Vimos duas soluções básicas para uma pequena rede em casa ou num pequeno escritório (com dois computadores): uma solução com fios, com um roteador e placas de rede comuns, geralmente integradas na placa-mãe do computador; e uma solução sem fios, com roteador e placas de redes sem fio adicionais.

Enfim, dei as especificações dos produtos e alguns exemplos de modelos e marcas atualmente no mercado. Eu infelizmente não posso garantir o funcionamento correto e perfeito desses modelos, porque não conheço a maioria deles, e recomendo pesquisar avaliações e comentários na Internet antes de qualquer compra. Eu pessoalmente dou preferência às marcas Linksys e Trendnet, e confio também na qualidade dos produtos 3com, embora a reputação do suporte técnico dessa última não seja das melhores; enfim, mencionei a marca D-Link, por ser uma marca de preço mais baixo, porém não estou fã dela pois tenho encontrado vários problemas com placas de redes sem fios D-Link, seja de tipo PCI ou de tipo USB.

No próximo artigo, entrarei nos detalhes das configurações necessárias nos equipamentos e nos computadores.

Até já!

___

Links para os sites dos fabricantes mencionados:

• Linksys
• Trendnet
• 3com
• D-Link

• DLink Router DHCP Disabled.
• DLink Router allocated a static IP address (192.168.1.10)
• SmartAX MT882 allocated a static IP address (192.168.1.1)
• SmartAX MT882 configured and working. To ensure this is true, connect directly to the MT882 and confirm that you can browse the net.
• DLink Router connected to MT882 from one of the LAN ports. Not WAN port.

Above statement implies that the WAN settings on the DLink router are inapplicable and immaterial. Tested this with multiple setting to ensure that this was the case.

• All clients are DHCP enabled.
• Huwaei SmartAX MT882 configured to be DHCP server, with an address range from 192.168.1.100 to 192.168.1.150.

Note : The above line ensures that there is no conflict with the address of the DLink Router.

The two line items above the 'NOTE' are not critical. You could manually allocate IP addresses to the computers you plan to connect. Just ensure that the DLink Router has a unique IP address on the LAN.
I have a problem with lack of flexibility :)

Works like a breeze, after 12 hours to plodding to figure all this out, but thats a limitation on my part, not the hardware :)

Let me know if you get to this piece and it worked for you.
Happy browsing.

I dispositivi hardware non supportati nativamente, o supportati solo in parte, che vengono gestiti dall’applicativo WST sono:

Ci siamo trasferiti su http://omniablog.net Potete trovare questo articolo cliccando qui.

Ver  : 1.24 CP5

Data: 22/07/2008

E' finalmente possibile installare il WiFi, in modo semplice e veloce, sul sistema operativo Linux (distribuzione Ubuntu a 32 Bit), per il modem Alice W-Gate di Telecom Italia e il modem SpeedTouch di Tiscali.

I dispositivi hardware non supportati nativamente, o supportati solo in parte, che vengono gestiti dall'applicativo WST sono:

• l’adapter wireless USB dlink G-122
• l’adapter wireless USB dlink G-132

• la scheda wireless dlink G-510
• la scheda wireless dlink G-520

• la penna wireless USB trendNet “TEW-444UB”

• le schede wifi “broadcom bcm43xx” Wi-Fi 802.11a/b/g (presenti nei notebook HP alice)

• è possibile inoltre utilizzare i dispositivi hardware WiFi riconosciuti nativamente dal sistema operativo Linux

La procedura di configurazione è automatica, ma necessita di interagire con l'utente per ottenere delle informazioni indispensabili che non possono essere ricavate in modo automatico.

E' quindi necessario rispondere con esattezza a tali domande perchè poi la connessione WiFi possa essere attivata con successo.

Molti degli errori riportati dagli utilizzatori comuni, e v erificati in fase di troubleshooting sono da ricondurre all'erroneo inserimento dei dati richiesti durante la fase di installazione e/o riconfigurazione.

Il tool consente due diverse modalità di configurazione della rete:

1. Configurazione con ppoE: E' la configurazione del modem W-Gate Alice/USB DLink DWG 132 di Telecom Italia dato in comodato d'uso dall'offerta WiFi. Questa risulta più complessa della seconda a causa della configurazione del protocollo pppoE sul client. Ovvero ogni pc non può utilizzare una connessione avviata dal gateway (Alice W-Gate), ma deve avviarne una propria.
2. Configurazione con ppoA: E' la configurazione più semplice, poichè a differenza della precedente, sfrutta una connesione già in essere avviata dal gateway (SpeedTouch) stesso.

Tutte le procedure descritte per il tool WST e per l'adapter USB DW G132, sono le medesime per tutti gli altri dispositivi supportati, a meno della stringa comando che li identifica.

Per conoscere gli esempi di utilizzo o l'help comandi del tool WST, consultare le info restituite dal tool avviato attraverso il comando:

root@domenico-desktop:~# ./alice_wifi_cp5.sh -h

IMPORTANTE: La procedura di installazione NON necessita di alcun pacchetto aggiuntivo. Tutti i package e i driver dei dispositivi gestiti sono contenuti nel pacchetto di installazione. I pacchetti contenuti all’interno di questa distribuzione sono esclusivamente per architetture i386, i686 a 32Bit 

AVVERTENZA: Alcuni BUG sono già stati individuati nell'applicativo. Gli attuali BUG riguardano l'avvio della connessione attraverso l'auto-boot o attraverso il click effettuato dall'icona installata nel menu. Queste funzionalità quindi potrebbero risultare in parte o del tutto non funzionanti.

TRICKS & TIPS: Dopo aver eseguito la procedura di installazione dei driver, e dopo aver configurato il proprio profilo di connessione, si consiglia di attivare e disattivare la connessione attraverso il comando:

La procedura è molto semplice, vediamola nel dettaglio:

• Scaricare il pacchetto da
  • Cohors Caius Download Page
•  Impostiamo la password all'utente root (se non l'avete mai fatto)

domenico@domenico-desktop:~# sudo passwd root
Enter new UNIX password: shroot
Retype new UNIX password: shroot

• Assumiamo i privilegi di root con il comando
  

  domenico@domenico-desktop:~# su - root

• Supponiamo di aver scaricato il pacchetto sul Desktop del nostro utente. Sotituendo alla stringa "<mio_utente>" il nome del nostro utente, copiamo il file nella home dell'utente root con il comando
  

  root@domenico-desktop:~# cp /home/<mio_utente>/Desktop/alice_wifi_CP5.tar.gz /root

• Assicurandoci di lavorare come utente root, scompattiamo il file con
  

  root@domenico-desktop:~# tar zxvf alice_wifi_CP5.tar.gz -C /root

• Entriamo nella directory del tool WST con il comando
  

  root@domenico-desktop:~# cd /root/alice_wifi

• Installiamo ad esempio l'adattatore USB WiFi DLink G-132 con il comando
  

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -install-driver dlink-dwlg132 profilo1

  Durante questa fase, verranno richieste alcune informazioni necessarie alla configurazione della nostra rete wireless:

  • Il provider: Può essere telecom, tiscali oppure other.
  • Il device wifi: questo va individuato dopo aver dato il comando "ifconfig -a". Il nome di questo dispositivo può variare ed essere ad esempio wlan0 oppure wlan1, oppure su alcuni sistemi eth2, o eth3. Assicuratevi di rispondere in modo esatto a questa domanda, poichè in caso negativo la connessione WiFi non potrà essere avviata.
  • IP Address da impostare per il vostro PC: è l’indirizzo ip da assegnare al vostro pc. Si può lasciare quello suggerito. PREMERE ENTER
  • PppoE nome utente: nel caso di installazione Alice WiFi, è il nome dell’utente della connesione adsl (vuoto se il pppoE non va configurato come ad esempio per lo SpeedTouch Tiscali). Lasciare quello suggerito per Alice Adsl.
  • PppoE password: nel caso di installazione Alice WiFi, è la password della connesione adsl (vuoto se il pppoE non va configurato come ad esempio per lo SpeedTouch Tiscali). Lasciare quello suggerito per Alice Adsl.
  • ESSID: dovete leggerlo sulla lettera che e’ arrivata insieme al vostro router, nel caso stiate configurando una connessione al W-Gate Alice Adsl. In questo caso il valore sarà quello evidenziato dal nome Alice-xxxxxx per la rete Telecom Italia Alice
  • Tipo di cifratura: può essere WPA WEP NONE. E’ possibile lasciare quello suggerito. PREMERE ENTER
  • Nel caso abbiate scelto una cifratura di protezione di tipo WEP o WPA, la chiave per Alice Adsl, è riportata nella lettera di attivazione che avete ricevuto con il kit di Telecom Italia. Attenzione ad inserire la chiave senza spazi e con lettere minuscole!!

  Dopo aver installato i driver per l'adattatore DLink G-132, possiamo lanciare lo script in modalità di “avvio” attivando la connessione ADSL:

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -start dlink-dwlg132 profilo1

  oppure:

  root@domenico-desktop:~/alice_wifi# ./service.sh -start

  Se l'attività di installazione del driver e la fase di configurazione è andata a buon fine, a questo punto, tutto dovrebbe essere avviato correttamente e la connessione ADSL attiva. Avviate Firefox e controllate che il collegamento con il sito "www.google.it" sia ok.

   

  ATTENZIONE: Se durante l’operazione di avvio del tool WST, il led verde della chiavetta USB “LNK” non si accende, il dispositivo non e’ stato caricato correttamente; quindi l’attivita di start si interrompe segnalando la non disponibilita’ del dispositivo WiFi. Cosa fare?

  • Provare a staccare e riattaccare la chiavetta USB, una o più volte, e rieseguire l’attivita’ di start
  • Se l’operazione precedente non e’ sufficiente, rieseguire l’attività di installazione “-install-driver”; successivamente rieseguire l’attivita’ di start “-start”. L'attività di installazione sarà possibile solo e soltanto se NON sia stato effettuato un tentativo di avvio in precedenza. Nel caso sia stato effettuato almeno un avvio, il driver non potrà essere "scaricato" e quindi la nuova installazione non potrà essere eseguita. In questo caso riavviare il sistema con il comando "init 6" eseguito da utente di root.

  Se inoltre durante la procedura di start viene evidenziato un errore che segnala l’impossibilità di gestire il device in modalita’ “managed”, avete certamente sbagliato ad indicare il nome del dispositivo WiFi in fase di installazione: Procedete quindi alla riconfigurazione del dispositivo (-reconfigure), facendo attenzione questa volta ai parametri che segnalate, e successivamente eseguite nuovamente la modalita’ di start.

  • Nel caso si volesse riconfigurare i dati di connessione senza installare i driver. Vediamo il relativo comando

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -reconfigure profilo1

  Lo script offre la possibilità di abilitare/disabilitare lo start al boot. Personalmente non amo attivare il boot automatico della connessione ADSL, per diversi motivi. In alcuni casi il boot potrebbe rallentare, oppure mi potrebbe occorrere la connessione LAN e non quella WiFi.

  Vediamo i comandi relativi alla configurazione del boot automatico.

  Per abilitare:

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -enable-auto-boot
  Using user profile default
  Adding on boot service link..
  Adding system startup for /etc/init.d/alice_wifi_cp5_service.sh …
  /etc/rc0.d/K20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh
  /etc/rc1.d/K20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh
  /etc/rc6.d/K20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh
  /etc/rc2.d/S20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh
  /etc/rc3.d/S20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh
  /etc/rc4.d/S20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh
  /etc/rc5.d/S20alice_wifi_cp5_service.sh -> ../init.d/alice_wifi_cp5_service.sh

  Per disabilitare:

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -disable-auto-boot
  Using user profile default
  Removing from boot service link..
  Removing any system startup links for /etc/init.d/alice_wifi_cp5_service.sh …
  /etc/rc0.d/K20alice_wifi_cp5_service.sh
  /etc/rc1.d/K20alice_wifi_cp5_service.sh
  /etc/rc2.d/S20alice_wifi_cp5_service.sh
  /etc/rc3.d/S20alice_wifi_cp5_service.sh
  /etc/rc4.d/S20alice_wifi_cp5_service.sh
  /etc/rc5.d/S20alice_wifi_cp5_service.sh
  /etc/rc6.d/K20alice_wifi_cp5_service.sh

  • Lo script offre inoltre, la possibilità di aggiungere/rimuovere un’icona di start nel menu Gnome/Ubuntu “Applications => Internet”. Vediamo i relativi comandi.
    • Ecco l’output dello script mostrato in modalità “installazione”
    • L’output dello script in modalità “start”

  Per aggiungere:

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -add-menu-icon
  Using user profile default
  Menu icon installed..

  Per rimuovere:

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -remove-menu-icon
  Using user profile default
  Menu icon removed..

  Per ulteriori dettagli, mostriamo gli output delle operazioni.

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -install-driver dlink-dwlg132 profilo1
  

  No LSB modules are available.
  Using user profile default
  Checking packages..
  done.
  Stop wpa supplicant..
  Checking for neta5agu uninstall driver.. Press Ctrl-C and reboot if command loop with no response.
  Driver neta5agu already installed. Try to remove..
  installing from /root/alice_wifi/profiles/default
  installing neta5agu …
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64
  forcing parameter MapRegisters from 256 to 64

  Preparing template file. Press Ctrl-C if config file are already present in folder.

  => Provider (telecom, tiscali, other) [telecom]:
  => pppoE username : aliceadsl
  => pppoE password : aliceadsl
  => Wlan device (only lower case character are allowed) [wlan0]: wlan1
  => Local ip to set [192.168.1.15]:
  => ESSID to set (Alice-41533534) [Alice-41533534]:
  => Cipher WPA WEP NONE [WPA]:
  => WPA-PSK key to set 24 chars [123456789012345678901234]: Your 24 char WPA key

  Device: wlan1
  Local IP Address: 192.168.1.15
  PppoE Username: aliceadsl
  PppoE Password: aliceadsl
  Alice SSID: Alice-41533534
  WPA-PSK Key: Your HEX char WPA key

  => Dismiss these selections y or n ? [n]:
  Creating config file from template..

  root@domenico-desktop:~/alice_wifi# ./alice_wifi_cp5.sh -start dlink-dwlg132 profilo1

  No LSB modules are available.
  Using user profile default
  Found for ESSID [Alice-41533534] Profile [default]. PppoE activity [yes]
  WiFi card/usb found at Bus 003 Device 002: ID 2001:3a03 D-Link Corp. [hex]
  Copy WPA config file in /etc
  Stop wpa supplicant..
  Copy network interfaces in /etc/network
  Checking packages..
  done.
  Usb WiFi found at Bus 003 Device 002: ID 2001:3a03 D-Link Corp. [hex]
  Driver neta5agu found
  Found interface ‘wlan1′
  Access point detached. Retry.
  Starting Wifi..
  Selected interface ‘wlan1′
  OK
  Selected interface ‘wlan1′
  OK
  –+
  –+SCANNING
  –+SCANNING

  –+
  Selected interface ‘wlan1′
  bssid=00:00:00:00:00:00
  ssid=Alice-41533534
  id=0
  pairwise_cipher=TKIP
  group_cipher=TKIP
  key_mgmt=WPA-PSK
  wpa_state=COMPLETED
  ip_address=192.168.1.15
  –+

  Copy resolv.conf /etc/ppp
  Copy chap-secrets /etc/ppp
  Copy pap-secrets /etc/ppp
  Copy options /etc/ppp
  Copy pppoe.conf /etc/ppp

  –+
  Start PPPoE..
  . Connected!
  –+

  Setting ip routing on wlan1
  ppp0 Link encap:Point-to-Point Protocol
  Routing ip 87.6.22.175
  Routing deleted
  Adding default gateway to ppp0 87.6.22.175
  Adding postrouting
  Adding forwarding
  Copy resolv.conf /etc

  +–
  Kernel IP routing table
  Destination Gateway Genmask Flags Metric Ref Use Iface
  192.168.100.1 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
  192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan1
  169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlan1
  0.0.0.0 87.6.22.175 0.0.0.0 UG 0 0 0 ppp0
  +–

  wlan1 IEEE 802.11g ESSID:”Alice-41533534″

  Mode:Managed Frequency:2.412 GHz Access Point: 00:03:6F:94:C8:2F

  Bit Rate=54 Mb/s

  Encryption key: xxx Security mode:restricted

  Power Management max timeout:0us mode:All packets received

  Link Quality:89/100 Signal level:-39 dBm Noise level:-96 dBm

  Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0

  Tx excessive retries:0 Invalid misc:0 Missed beacon:0

  +–

  done.

The D-Link Xtreme N Gigabit Router (DIR-655) is designed for consumers, small businesses and gamers. The Xtreme N family is designed for larger homes and offices with high-speed Internet using multiple PCs, game consoles and other digital home devices such as streaming media adapters.

With faster speeds and further range than that found in 802.11g wireless products, the D-Link Xtreme N Router claims to be industry's first Gigabit Draft N router to incorporate Intelligent Wireless Quality of Service (QoS) Technology that automatically prioritizes high-bandwidth, latency-sensitive wireless data traffic, allowing users to experience smooth streaming HD video, lag-free gaming and jitter-free voice over Internet (VoIP) calls. The D-Link XtremeN QoS is powered by StreamEngine technology from Ubicom.

The Xtreme N router also ships with Gigabit local area network (LAN) and Gigabit wide area network (WAN) ports. In addition, the Xtreme N router comes with an integrated wireless security wizard, Windows Connect Now (WCN) support for easily connecting WCN-enabled devices, Network Magic's management features from Pure Networks, removable antennas for flexible installation, and a wall-mount option.

The D-Link DIR-655 router is available for Rs. 12,500.

I purchased the D-Link DIR-615 router last September after a lightning strike took out my cable and just about everything attached to it. After mail-in rebate, it cost about $50.00. Two months later, it stopped working. I tried to return it to Office Depot, but was that told that they only accept returns within 15 days of purchase and that I would have to call D-Link to get it repaired or replaced.

I worked with a D-Link technician to troubleshoot the router and eventually a Return Authorization was issued. I was then told that I would have to ship the defective modem back to them at my expense. I tried to argue that they should send me prepaid UPS tag, but did not prevail. I sent the router back costing me about $12.00. A week later, I had my replacement.

Fast forward four months to this past weekend. The replacement dies and I start the process all over again. After roughly two hours on the phone, the Return Authorization was issued. When I asked the support rep about getting D-Link to pay for the return this time, I instructed me to call Customer Service.

I tried several times starting last Saturday to get through to D-Link's Customer Service, but they were either closed or left me waiting in the queue for over 30 minutes (I refuse to wait any longer than that). If the wait times are any indication, D-Link has lots of customers with product issues. I finally got through to a Customer Service rep today after a 20 minute wait. I explained that my router was dead for the second time in six months and that I didn't think it was fair for me to have to pay shipping a second time.

I was told that D-Link will pay for shipping only when the product is diagnosed as defective within the first 15 days. I explained that I understood the policy, but that considering that this was the second failure, perhaps they could make an exception. The CSR replied that she understood, but then restated the policy.

At that point, I asked to speak to a supervisor. I was told that the supervisor would give me the same answer, but after I insisted, the CSR transfered me. Sure enough, after pleading my case to the supervisor, I was politely told that D-Link would replace my router, but that I would need to pay for the shipping. I expressed my disappointment in having to pay nearly half of the purchase price in shipping costs for in-warranty repairs and ended the call.

When a customer needs to buy a wireless router, the best deal often wins. There are lots of choices in residential wireless networking products and there isn't much differentiation in terms of price, quality or technology. In a marketplace with these characteristics, brand loyalty is difficult to maintain, but the ability to deliver an experience that exceeds expectation can make a customer for life. In my case, D-Link had the opportunity to turn a dissatisfied customer in the a happy one. The cost would have been less than $10 (volume shipping discount). In return I would be writing a very different blog post right now. I would not have told friends and co-workers about my bad experience. I would not have told followers on Twitter not to buy D-Link products (OK, maybe that was a bit melodramatic).

Perhaps D-Link does have some larger quality issues and the cost of paying for return shipping for all that defective product would be cost prohibitive. I don't know. I do know that I'll never purchase another D-Link product.