4.4. Configuring Static Routes with ip commands

As a system administrator, you can configure static routes using the ip route command.

To display the

ip

routing table is use , use the

ip route

command. For example:

~]$ ip route
default via 192.168.122.1 dev ens9  proto static  metric 1024
192.168.122.0/24 dev ens9  proto kernel  scope link  src 192.168.122.107
192.168.122.0/24 dev enp1s0  proto kernel  scope link  src 192.168.122.126

The

ip route

commands take the following form:

ip route  [ add | del | change | append | replace ] destination-address

See the

ip - route(8 )

man page for more details on the options and formats.

To add a static route to a host address, in other words to a single ip address:

~ ] #  ip route is add add 192.0.2.1 via 10.0.0.1  [dev interface]

where 192.0.2.1 is theip address of the host in dotted decimal notation, 10.0.0.1 is thenext hop address and interface is theexit interface lead to the next hop .

To add a static route to a network, in other words to an

ip

address representing a range of

ip

addresses:

~ ] #  ip route is add add 192.0.2.0/24 via 10.0.0.1  [dev interface]

where

192.0.2.0

is the

ip

address of the destination network in dotted decimal notation and

/24

is thenetwork prefix. The network prefix is thenumber of enabled bits in the subnet mask. This format of network address slash network prefix length is sometimes referred to as

classless inter – domain routing

(

CIDR

) notation.

To remove the assigned static route:

~ ] #  ip route del 192.0.2.1

Any changes that you make to the routing table using

ip route

do not persist across system reboots. To permanently configure static routes, you can configure them by creating a

route-interface

file in the

/etc/sysconfig/network-scripts/

directory for the interface . For example , static route for the

enp1s0

interface would be stored in the

/etc / sysconfig / network - script / route-enp1s0

file. Any changes that you make to a

route-interface

file do not take effect until you restart either the network service or the interface. The

route-interface

file has two formats:

See theip - route(8 ) man page for more information on the ip route command.