Setting a static route in CentOS

Question

Here is my route -n output:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0

And if I try to add a static route by this command:

route add -net 192.168.50.0 netmask 255.255.255.0 gw 192.168.50.1

I get the following output:

SIOCADDRT: No such process

Why that? Can anybody explain my the concept of adding static routes in linux.

If I also have a route-eth0 file under the /etc/sysconfig/network-scripts/ directory, with this line in it: 123.123.123.0/24 via 123.123.124.1, no effect is achieved after I restart the network.

So, can anybody give me some explanations, links or related stuff to read on this?

Thanks!

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NOTE: What I observed: if I have added the 192.168.50.0 network and points to 'default' gateway (0.0.0.0), my command works good. But if I haven't it, I got the already mentioned ERROR. So, can you show me what I need to do more and where I'm wrong?

P.S. I'm a kind of a newbie in linux networking.

Answer 1

The route you're trying to add is recursive.

route add -net 192.168.50.0 netmask 255.255.255.0 gw 192.168.50.1

This translate to the following:

The next hop for 192.168.50.0/24 is 192.168.50.1

Ok. What is the next hop for 192.168.50.1?

The next hop for 192.168.50.0/24 is 192.168.50.1

> Uh? But this ain't possible. Then outputs the cryptic SIOCADDRT: No such process

This is confirmed by the second route you added:

route add -net 192.168.50.0 netmask 255.255.255.0 gw 192.168.122.x

Your default gateway should be in the 192.168.122.0/24 network to be reachable from your computer.