How do we add a route to linux system? what if we have to define custom routes for networking scheme required in my environment? How to use linux route command to show, add or modify the current routing table?
in order to modify the routing table, we can use any of the two commands;
ip route or
route. Both shows their magic and achieve the same goal of adding, deleting or modifying route parameters.
Display Current Routing Table
From the terminal, issue the following command
# ip route list
Output will look something like this:
[root@redHat~]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default 192.168.1.1 0.0.0.0 UG 100 0 0 ens192 10.21.0.0 0.0.0.0 255.255.0.0 U 100 0 0 ens192 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
Additionally, following commands can be executed as well:
# route -n
# ip route show
Linux Add a Default Route using route add command
# route add default gw 192.168.1.1 dev ens192
Linux add a default gateway via ens192 using ip route add commmand
# ip route add 192.168.1.0/24 dev ens192
Added routes can be verified using the above commands i.e
ip route or
Persistent route in Red Hat, Centos or Fedora
If you wish to add the routes and let them stay persistent regardless of the system reboots, edit the following configuration file in rpm based operating systems.
# vi /etc/syconfig/network