what is "ip route x.x.x.x/x loopback1" for?

[rock830906]

When do we use such a configuration like "ip route x.x.x.x/x loopback1".A static route point to loopback interface.

And What is the difference between loopback and null0 in a static route

[Richard Burts · Accepted solution]

A static route which has a loopback specified as the outbound interface is functionally the same as a static route which specifies null0 as the outbound interface. What both things do is to create a static route that will always be in the routing table.

As far as I know there is very little difference between a static route with a loopback and a static route with null0. One difference that I know of is that a loopback interface can be shutdown and if that happens the static route will no longer be in the routing table. I am not sure that you can do that with null0.

HTH

Rick

[rock830906]

Thank you very much!