send to MAC A, reply from MAC B, same IP. Whats going on ? Jun 13 2007 12:33AM
curiouscode (cheapchinni yahoo com) (1 replies)

I have a linksys wireless AP and router. I have been monitoring my ethernet
traffic on the wireless laptop (cant put the card into promiscuous mode), so
I know I cant see all the traffic that is out there.
I have WEP and I know its trivial to break it, I am suspicious it has been
broken, but I have not changed the key- because I need to prove it to my SO
that we need to get WAP.

I noticed something odd yesterday. This is my configuration: 1 wireless
laptop A, one computer wired directly connected to router with cable, B
router ip:
Wireless PORT on the router: 00:11:22:33:44:55:90
Port to which wired Computer B is connected: 00:11:22:33:44:55:8E

Arp table on wireless computer shows: -->00:11:22:33:44:55:8E
since the MAC address is that of the wired port, I was wondering what is
going on, so I made a static arp entry in wireless comp A -->00:11:22:33:44:55:90

Something I did not expect happened,as I watehced the packets with ethereal.
My outgoing packets has ethernet address of the actual wireless port MAC,
which I just added ie., 00:11:22:33:44:55:90, BUT the incoming packets has
the reply coming from 00:11:22:33:44:55:8E.

My questions:
Is there a logical explanation for this ?
If someone was masquerading as 00:11:22:33:44:55:8E/ AP, would
that not cause a problem with the real AP having 8E as a port(wired port)
Can there be NICS on the same network with same mac-address -what happens
then ?
Since my wired computer A is connected to the physical 00:11:22:33:44:55:8E
port, can someone who is a wireless NIC of the same MAC 00:11:22:33:44:55:8E
-hear traffic from my wired computer-which is destined for the router ?


View this message in context:
Sent from the Incidents mailing list archive at

This list sponsored by: SPI Dynamics

ALERT: .How a Hacker Launches a SQL Injection Attack!.- White Paper
It's as simple as placing additional SQL commands into a Web Form input box
giving hackers complete access to all your backend systems! Firewalls and IDS
will not stop such attacks because SQL Injections are NOT seen as intruders.
Download this *FREE* white paper from SPI Dynamics for a complete guide to protection!

[ reply ]
Re: send to MAC A, reply from MAC B, same IP. Whats going on ? Jun 13 2007 11:32PM
Jason Muskat, GCFA, GCUX, de VE3TSJ (Jason TechDude Ca)


Privacy Statement
Copyright 2010, SecurityFocus