I am using CentOS 6. I have managed to add and delete static routes (using route add and route del commands, respectively), and now my routing table is the way I want it. It looks like this:

Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
111.68.222.48 0.0.0.0 255.255.255.240 U 0 0 0 eth1
10.1.8.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.0.0 10.1.8.1 255.0.0.0 UG 0 0 0 eth0
0.0.0.0 111.68.222.49 0.0.0.0 UG 0 0 0 eth1

What do I need to do to make this routing table persistent? I know it involves creating a file or two in /etc/sysconfig/network-scripts/, but which files do I need to create and what goes in each file?

If you read /etc/sysconfig/network-scripts/ifup-routes, you'll see the naming convention
Its not a long file; have a good read.

What I gather by reading /etc/sysconfig/network-scripts/ifup-routes is that I have to create the following two files:

1. /etc/sysconfig/network-scripts/route-eth0
2. /etc/sysconfig/network-scripts/route-eth1

So, if I want my routing table to look like this:

Destination Gateway Genmask Flags MSS Window irtt Iface
111.68.222.48 0.0.0.0 255.255.255.240 U 0 0 0 eth1
10.1.8.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.0.0 10.1.8.1 255.0.0.0 UG 0 0 0 eth0
0.0.0.0 111.68.222.49 0.0.0.0 UG 0 0 0 eth1

Then I should put the following in route-eth0:

ADDRESS0=10.1.8.0
GATEWAY0=0.0.0.0
NETMASK0=255.255.255.240
ADDRESS1=10.0.0.0
GATEWAY1=10.1.8.1
NETMASK1=255.0.0.0

And I should put the following in route-eth1:

ADDRESS0=111.68.222.48
GATEWAY0=0.0.0.0
NETMASK0=255.255.255.240
ADDRESS1=0.0.0.0
GATEWAY1=111.68.222.49
NETMASK1=0.0.0.0

Am I on the right track, or have I totally missed the mark???

It seems that the CentOS 5 documentation on static routes is applicable to CentOS 6
http://www.centos.org/docs/5/html/5....ic-routes.html

I don't know about CentOS 5 but on CentOS 6 you can just use lines like
10.2.7.0/24 via 10.1.0.7
10.5.0.0/16 via 10.1.0.8
to specify that traffic for
10.2.7.0 with netmask 255.255.255.0 goes via 10.1.0.7 and
10.5.0.0 with netmask 255.255.0.0 goes via 10.1.0.8
You seem to be able to skip putting on the last 2 parameters, such as "dev eth0" that are mentioned on the CentOS doc page.

I personally prefer this format as it seems neat in comparison to using multiple lines per route so if you have something like
10.1.0.0/16 via 10.2.0.4
10.3.0.0/16 via 10.2.0.4
10.4.0.0/16 via 10.2.0.4
10.5.0.0/16 via 10.2.0.4
10.6.0.0/16 via 10.2.0.4
10.7.0.0/16 via 10.2.0.4
10.8.0.0/16 via 10.2.0.4
10.9.0.0/16 via 10.2.0.4
10.10.0.0/16 via 10.2.0.4
it is very neat way to specify 9 static routes.

If you don't know how to convert between the CIDR and netmask notation have a read of these links
http://en.wikipedia.org/wiki/IPv4_subnetting_reference
http://en.wikipedia.org/wiki/Classle...Domain_Routing

I'm afraid this information does not really help me. I would request someone to please have a look at my comments again and see if they have some suggestions.