Reverse ARP

Jean Tourrilhes jt at
Wed Oct 24 02:46:06 EST 2001

Chandana Pairla wrote :
> Hi,
> Just wondering if anyone spent time on this...
> The ioctl to the Aironet card returns the MAC address of the AP. I would
> like to extract the IP address of the AP. I could use rarp but it is not
> functional in the latest kernels...and I read it is being phased out. And I
> know you can get the IP address because I am using a cisco utility that
> displays the IP address of the AP...ofcourse since I dont have the source
> for it, I cant see how they are doing it. Perhaps someone has an idea how to
> do this?
> Thanks and Regards,
> C.
> Chandana Pairla

	A Wireless Access Point is a bridge, operating at layer 2, and
therefore is not required to have an IP address. In fact, I've got a
few Access Points that don't have any IP address (and no TCP/IP stack
either). 802.11 doesn't talk about TCP/IP at all, so there is no
guarantee that the IP address of the AP exist.
	Moreover, all AP are usually shipped with the same default IP
address, so there is no guarantee of unicity, and no guarantee that
the IP address is valid on the present subnet.
	I think that the IP address stuff is a proprietary extension
and if you mix card/AP from different vendors the card won't be able
to get the IP address of the AP (but I didn't check).
	So : good luck...


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