Linux router->proxy_arp? route daemon?

[unhappy_mage]

First off, not sure whether this would be better addressed here or in the linux forums. Mods, please feel free to move me.

I've got a Linux router box which routes between 2 subnets, 192.168.1.0/24 and 10.0.0.0/8. The machine gives out DHCP leases on the 10 subnet, so they all have it set as default gateway. However, the problem is that the 192 machines can't talk to the 10 machines because they are not dhcp-assigned and so they all have different gateways. I could set up static routes on all of these machines saying that the 10 network is accessible through the router over there, but there are quite a few and it'd be a pain to change them all should my router's IP change.

So, the question is this: how can I have my router announce itself to the 192 network so that the 10 network can talk to the 192s?

According to the links I've provided, it seems proxy_arp does this for single networks by breaking them into subnets. (How) can I get this going for two seperate networks?
References:
http://linux-ip.net/html/adv-proxy-arp.html
http://linux-ip.net/html/ether-arp.html

 

[BollWeevil]

Proxy arp is not what you are looking for in this situation. Proxy arp is used when a machine has an IP address in the same subnet as another, but the machines reside on separate network segments. Thus, the bridge/router between the segments allows forwarding of ARP packets, and acts as a proxy for any MAC that needs to cross to a different segment.

However, the TCP/IP stack of a machine will never send an arp query for an IP address that is not on the same subnet, by definition of subnetting. For a different subnet it always sends to the default gateway instead of arping.

The only solution to your problem is to enter static routes, or to statically set the router as the 192.168.x machines' gateway.