RTNETLINK answers: No such process - Redhat , RHEL , Centos

Found on - Centos Linux 5 and 6

Cause:

• Routes can only be added for directly connected subnets. Use ifconfig to make sure that the subnet you are trying to add the route through exists.
• Red Hat can assist with the syntax of adding routes. However only the customers network administrator understands the network topology and therefore needs to provide the correct parameters for the ip route command.

Solution:-

Example solution:

# ifconfig
ethX       Link encap:Ethernet   
          inet addr:192.168.1.12  

# ip route add 2.2.2.2/29 via 1.1.1.1 
RTNETLINK answers: No such process

But the following works, as my router is 192.168.1.1 and br0 are on the same subnet:

# ip route add 2.2.2.2/29 via 192.168.1.1