Cisco PIX's used to do this if the firewall had a route and saw a ARP request in that IP range it would proxy arp.
----- Original Message ----- > > On Jan 15, 2014, at 4:03 PM, Niels Bakker <niels=na...@bakker.net> wrote: > > > * c...@bloomcounty.org (Clay Fiske) [Thu 16 Jan 2014, 00:59 CET]: > >> This is where theory diverges nicely from practice. In some cases the > >> offender broadcast his reply, and guess what else? A lot of routers > >> listen to unsolicited ARP replies. > > > > I've never seen this. Please name vendor and product, if only so other > > subscribers to this list can avoid doing business with them. > > This was some time ago, but the two I was able to dig up from that case were > both Junipers. Perhaps it’s something that only happens when proxy ARP is > enabled? > > > -c > > > -- Eric Rosen CCIE Security #17821 Information Security Analyst Red Hat, Inc ero...@redhat.com 919.890.8555 x48555 IRC erosen