I was being shown this message but I knew the operating system was refusing to add the route
root@linux:~ # route add -net 172.22.1.0 gw 172.22.18.1 netmask 255.255.255.0 dev eth1
SIOCADDRT: No such process
I added the route to /etc/sysconfig/network/routes and then restarted the network service
192.168.1.1 192.168.233.2 255.255.255.255 eth1
148.91.0.0 172.22.18.1 255.255.0.0 eth1
207.169.17.0 172.22.18.1 255.255.255.0 eth1
172.22.0.0 172.22.18.1 255.255.255.0 eth1
172.22.14.0 172.22.18.1 255.255.255.0 eth1
172.22.1.0 172.22.18.1 255.255.255.0 eth1
default 172.22.240.1 – –