Routing Problem on Multihomed Machine
 

I have a Archlinux machine with 2 nics, each on a seperate subnet. The networks are 192.168.1.0/24 and 10.7.7.0/24. Default gateway to outside world is 192.168.1.1 on a different machine. I have been trying to simply route traffic between subnets and am failing miserably. The router is also my dns/dhcp server hopefully for both subnets when im done. I have dropped the firewall and made triple sure forwarding is enabled. From 10.7.7.5 for example i can ping both nics (10.7.7.1 and 192.168.1.25) on the server but nothing else on the opposing subnet or internet. My servers route shows this

[root@Penguin /]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
10.7.7.0 * 255.255.255.0 U 0 0 0 eth1
default gateway1.lan.or 0.0.0.0 UG 0 0 0 eth0
[root@Penguin /]#


My ifconifg shows ...

[root@Penguin ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:10:18:01:24:9A
inet addr:192.168.1.25 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::210:18ff:fe01:249a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6126 errors:0 dropped:0 overruns:0 frame:0
TX packets:5159 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:417381 (407.5 Kb) TX bytes:3141675 (2.9 Mb)
Interrupt:10

eth1 Link encap:Ethernet HWaddr 00:10:18:01:28:DF
inet addr:10.7.7.1 Bcast:10.7.7.255 Mask:255.255.255.0
inet6 addr: fe80::210:18ff:fe01:28df/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:81 errors:0 dropped:0 overruns:0 frame:0
TX packets:57 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:11983 (11.7 Kb) TX bytes:9524 (9.3 Kb)
Interrupt:5

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:160 errors:0 dropped:0 overruns:0 frame:0
TX packets:160 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:16160 (15.7 Kb) TX bytes:16160 (15.7 Kb)


Does anyone have any suggestions as to what im missing here, i simply want traffic between the subnets to flow.

Best advice i got off this board which was to use tcpdump and ethreal to figure it out. Default gateway on the 192.168.1.0 network was the culprit, pings were goin to right spot but the reply was being shipped off into the internet :)