On Thu, Mar 06, 2008 at 05:58:20PM +0100, Ralf Ertzinger wrote: > On Thu, 6 Mar 2008 15:54:35 +0100, Lennart Poettering wrote: > > NAT yes, of course. > > > > proxy arp, no. If you have a route like "route add default dev eth0" > > this will cause all packets to be adressed to the broadcast MAC > > address. All other ethernet devices on the same segment should get > > packets labelled that way because they listen for both their own MAC > > address and the broadcast MAC address. > > I'm sorry, but that's just wrong. Setting a net route on a broadcast > device will cause ARP request for the IP addresses in that network > to be broadcast on that segment. Nothing more, nothing less. A host has > to respond to these requests for routing to occur (most likely though > proxy arp). The only thing being sent with a broadcast MAC are the ARP > requests, but those are always sent this way. Ralf is, of course, correct. [1] In a sense the only purpose of the routing table is to control which IP address gets ARPed when sending-out a frame. Setting the default route to "dev eth0" just means you ARP for any address. Just to make sure, I replicated this environment on my local LAN. Simply setting the default route as "dev eth0" left me with a laptop that could only reach the local LAN. Turning on proxy arp at my NAT router enabled me to communicate with the Internet. I encourage you to replicate my experiment. :-) It's possible that there is some other setting that turns-on the behavior you describe. But if there is, I don't know about it. Thanks, John [1] Conveniently, that means I am correct as well. :-) -- John W. Linville linville@xxxxxxxxxx -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
