How to add static and temporary route on Linux server

Temporary Route:

First add temporary route on the server & note down the configuration that is shown on the server using below command

ip route add 172.22.126.18 via 172.22.97.4 dev eth0

ip route add 172.22.126.19 via 172.22.97.4 dev eth0 Once you add the route using above commands check the output of  route -n command.It will give you an idea regarding default netmask

[root@connector ~]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

172.22.127.249  172.22.124.7    255.255.255.255 UGH   0      0        0 eth0

172.22.124.0    0.0.0.0         255.255.254.0   U     0      0        0 eth0

169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth0

0.0.0.0         172.22.124.1    0.0.0.0         UG    0      0        0 eth0

Now after service restart the routing configurations taken by above command will be removed.

but if you want to add static routes you can follow below steps

Static Route:

I have created route-eth0 file & made the below changes & can confirm that static routes have been added.

The below configuration is persistent after service network restart

1.cd /etc/sysconfig/network-scripts
2.vi route-eth0
append the below lines ADDRESS0=172.22.126.18 NETMASK0=255.255.255.255 GATEWAY0=172.22.97.4 ADDRESS1=172.22.126.19 NETMASK1=255.255.255.255 GATEWAY1=172.22.97.4
3.Service network restart
The below configuration is persistent after service network restart

[root@connector network-scripts]# cat route-eth0

ADDRESS0=172.22.126.18

NETMASK0=255.255.255.255

GATEWAY0=172.22.97.4

ADDRESS1=172.22.126.19

NETMASK1=255.255.255.255

GATEWAY1=172.22.97.4

[root@connector network-scripts]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

172.22.126.18   172.22.97.1     255.255.255.255 UGH   0      0        0 eth0

172.22.126.19   172.22.97.1     255.255.255.255 UGH   0      0        0 eth0

192.168.38.0    0.0.0.0         255.255.255.0   U     0      0        0 eth3

192.168.36.0    0.0.0.0         255.255.255.0   U     0      0        0 eth1

192.168.37.0    0.0.0.0         255.255.255.0   U     0      0        0 eth2

172.22.97.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0

169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0

169.254.0.0     0.0.0.0         255.255.0.0     U     1003   0        0 eth1

169.254.0.0     0.0.0.0         255.255.0.0     U     1004   0        0 eth2

169.254.0.0     0.0.0.0         255.255.0.0     U     1005   0        0 eth3

0.0.0.0         172.22.97.1     0.0.0.0         UG    0      0        0 eth0

#ip route add 172.22.126.18 via 172.22.97.4 dev eth0
#ip route add 172.22.126.19 via 172.22.97.4 dev eth0