On a Red Hat Enterprise Linux Server release 5.4 (Tikanga) system,
I set up a static route that unfortunately seems to get ignored.

I set up the static route in the file /etc/sysconfig/network-scripts/route-eth0 as follows:

172.16.96.2/32 via 192.168.219.251

I've restarted the network service and also rebooted a few times.

Here’s my current routing table:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.16.96.2 192.168.219.251 255.255.255.255 UGH 0 0 0 eth0
192.168.219.0 * 255.255.255.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default 192.168.219.250 0.0.0.0 UG 0 0 0 eth0

I am able to ping 172.16.96.2. However, when I do traceroute 172.16.96.2, it appears that the traffic goes through the default gateway 192.168.219.250 instead of our requested specific gateway 192.168.219.251:

[root@colt-vm-4019c ~]# traceroute -n 172.16.96.2
traceroute to 172.16.96.2 (172.16.96.2), 30 hops max, 40 byte packets
1 192.168.219.250 0.511 ms 0.768 ms 0.753 ms
2 172.16.97.1 3.466 ms 3.452 ms 3.434 ms
3 * * *

I can ping both 192.168.219.251 and 192.168.219.250.

In the route-eth0 file, I’ve also tried using the alternate syntax with ADDRESS0=<IP address> etc, but it didn’t work any better. I also tried setting a more general route of

172.16.96.0/24 via 192.168.219.251

But this also didn’t help.

The System / Administration / Network tool previously showed a spurious extra NIC called eth0.bak in addition to eth0. I deleted the eth0.bak and rebooted, but this also didn't help. Currently, eth0 is the only NIC on the system.

Thanks in advance for any workarounds or diagnostic tips.
--Joseph

I've used iptables snat/dnat prerouting/postrouting rules to do this before. Google/man page it.

Thanks fuubar2003. I belatedly discovered that this was a spurious problem. The traceroute command was not reporting the first hop that the packet took. When I ran tshark on the desired device, I was able to see that the packet was really arriving as expected. Live and learn, I guess.
-- Joseph