On 3/26/2011 7:16 PM, Jeroen van Ingen wrote:
With regard to proxy-arp and CAM table overflow: sorry, but I don't see
that happening, not if we're still talking about CAM in the sense of
"layer 2 forwarding tables".
With proxy-arp enabled, a router will reply to any ARP request for
addresses in networks that are reachable from the router (possibly
including "default" route). However, the router will reply with its own
MAC address; both as L2 source which is relevant for any intermediate
switches, and with its MAC in the ARP payload which is relevant to the
host that did the ARP request.
No matter how many times the router acts as a proxy (by replying to ARP
requests for host addresses on other networks), the router will only use
one distinct source MAC for all packets it sends into the VLAN. And only
the source MAC in a layer 2 frame is considered when building L2
forwarding tables.
Regards,
Jeroen van Ingen
Very true. I was thinking from the POV of a L2 switch without a gateway
relying on proxy ARP. Unfortunately I've seen that too many times.
_______________________________________________
cisco-nsp mailing list [email protected]
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/
