Topics: AIX, Networking

Adding and deleting a static network route using the command line

There are two commands that can be used to add a route on an AIX system.

The first one is route, and can be used to temporarily add a route to an AIX system. Meaning, if the system is rebooted, after the route has been added, the route will be lost again after the reboot.

The second command is chdev -l inet0 that can be used to permanently add a route on an AIX system. When this command is used, the route will persist during reboots, as this command writes to information of the route in to the ODM of AIX.

Let's say you have a need to add a route on a system to network 10.0.0.0. And that network uses a netmask of 255.255.255.0 (or "24" for the short mask notation). Finally, the gateway that can be used to access this network is 192.168.0.1. Obviously, please adjust this to your own situation.

To temporarily add a route on a system for this network, use the following route command:

# route add -net 10.0.0.0 -netmask 255.255.255.0 192.168.0.1
After running this command, you can use the netstat -nr command to confirm that the route indeed has been set up:
# netstat -nr | grep 192.168.0.1
172.30.224/24   192.168.0.1   UG   0   0   en1   -   -
To remove that route again, simply change the route command from "add" to "delete":
# route delete -net 10.0.0.0 -netmask 255.255.255.0 192.168.0.1
Again, confirm with the netstat -nr command that the route indeed has been removed.

Now, as mentioned earlier, the route command will only temporarily (until the next reboot) add a route on the AIX system. To make things permanent, use the chdev command. This command takes the following form:

chdev -l inet0 -a route=net,-netmask,[your-netmask-goes-here],-static,[your-network-address-goes-here],[your-gateway-goes-here]

For example:
# chdev -l inet0 -a route=net,-netmask,255.255.255.0,-static,10.0.0.0,
192.168.0.1
inet0 changed
This time, again, you can confirm with the netstat -nr command that the route has been set up. But now you can also confirm that the route has been added to the ODM, by using this command:
# lsattr -El inet0 -a route | grep 192.168.0.1
route net,-netmask,255.255.255.0,-static,10.0.0.0,192.168.0.1 Route True
At this point, you can reboot the system, and you'll notice that the route is still there, by repeating the netstat -nr and lsattr -El inet0 commands.

To remove this permanent route from the AIX system, simply change the chdev command above from "route" to "delroute":
# chdev -l inet0 -a delroute=net,-netmask,255.255.255.0,-static,10.0.0.0,
192.168.0.1
inet0 changed
Finally, again confirm using the netstat -nr and lsattr -El inet0 commands that the route indeed has been removed.



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