Using Ethereal to Bypass Dialer Software

Intro

A while back I was getting sick of using the dialer software for NetZero and having that damn icon in my taskbar. At first I tried just using my plain username and password in Windows dialup networking but it didn’t work. So I used Ethereal to capture what the dialer sent and after a little trial and error I figured it out.

So if you have dialup and your ISP forces their software down your throat, try this method to fool them.

You’ll need:

Ethereal – network protocol analyzer
WinPcap – packet capture library used by Ethereal

You’ll also need to know one of the phone numbers for your ISP in your area.

The procedure

Open Ethereal and press Ctrl+K to start a new capture. We’re not going to use any filters so just click OK. You’ll now see a window that shows the number of packets captured (zero so far :)).

Open up the dialer and connect.

When it’s connected click the Stop button in Ethereal.

Now you’ll see a list of packets in the top frame. We’re looking for a “PPP PAP Authenticate-Request” packet… so sort the list by Protocol. There should be two of them. Click on one.

In the middle frame it shows information about the packet. In the bottom frame it shows the contents of the packet.

You should see something like this in the middle frame (the numbers will probably be different):

Quote:

---

PPP password Authentication Protocol
Code: Authenticate-Request (0x01)
Identifier: 0x0c
Length: 49
Data (45 bytes)
Peer ID length: 33 bytes
Peer-ID (33 bytes)
Password length: 10 bytes
Password (10 bytes)

---

When you click on “Peer-ID (33 bytes)” it will highlight the username in the bottom frame. When you click on “Password (10 bytes)” it will highlight the password. Write these down somewhere.

Now that you have all the info you need, go into the Control Panel then into “Network and Dial-up Connections.” Double-click “Make a New Connection” and follow the connection wizard. You’re done :D

I’m fairly sure this method will work for other ISP’s than NetZero. Might help out you AOL (yuk) users :p Anyways I hoped you enjoyed my short but sweet tutorial.

mjk

I used almost exactly the same methodology to bypass my ISP's dialer. Except in my case, I searched for my username rather than a PPP PAP packet since I wasn't sure what authentication scheme was being used. Also, my dialer was PPPoE and not good ol' PPP. A slightly more detailed version of what I did (or at least why I did it) can be found here

Cheers,
cgkanchi

PS: Good work! Though a little more explanation of the concepts involved would be nice.