how-to block ads
|
|
Share Topic
 |
 |
|
 msjPremium
join:2004-05-21
Fort Collins, CO
kudos:1 | reply to bigjoesmith
Re: DHCP Spoofing / Half Bridging said by bigjoesmith:So, as implemented on the Speedtouch, DHCP-spoofing is not just a simple transparent layer 2 bridge. It functions more like a layer 3 IP router, but with some special characteristics thrown in. I hope this provides some insight into what DHCP-spoofing provides the end-user and how it's implemented on one modem. Thanks, that showed me a different way of doing it. I simulated this alternate method (used on the Speedtouch) with some manual configuration on my Actiontec running OpenWRT and got it to work.
I'm curious what netmask you obtain via DHCP from the modem. My guess is 255.255.255.255. What is the output from running ipconfig on your PC? | |
Reviews:
 ·Future Nine Corp..
1 edit | said by msj:I'm curious what netmask you obtain via DHCP from the modem. My guess is 255.255.255.255. What is the output from running ipconfig on your PC? The netmask that my computer obtains from the DHCP-spoofing modem is 255.255.0.0. So, you ask, how does my computer talk to any host with the same network, since it will think it's directly accessible? It works the same way that the default gateway is accessed, as descibed above. Basically, the modem will answer any arp request for any host on that network. In other words, the modem will answer an arp request for any 168.103.x.y request. (In this case, my local computer has gotten a 168.103.x.y IP address from the modem, so the network portion is 168.103 in this case.) The computer will send the packet to the modem, and the modem will send it on to the ISP's gateway.
So the modem will answer arps for any address in the computer's network (other than the computer's specific address, I suppose) and will also answer arps for the default gateway's specific address (which may not be in the same network as the computer's network). It will not answer arps for any other hosts in the default gateway's network, if that network is different from the computer's network. | | |
|
|
