ip route permanent

[leowchongwei]

there's a permanent option at the last part of "ip route" command. what's the difference if i add in the permanent or i do not add in? And where do i check whether an ip route has the permanent option?

[psijnja]

Normally, a route is only valid if the interface it points to is up. With the permanent statment, the route wil stay active even if the interface is shut down.

see link

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122sup/122csum/csum1/122csip2/1sfindp1.htm#1018069

[leowchongwei]

any idea how to check if an ip route statement is permanent?

[psijnja]

I think you can check it via sh route..

It should show as permanent in the type field

[milan.kulik]

If your sh ip route is specific enough, it will show you the permanent type:

gw#sh ip route 172.26.1.0

Routing entry for 172.26.1.0/24

Known via "static", distance 1, metric 0

Routing Descriptor Blocks:

* 10.100.0.2, permanent

Route metric is 0, traffic share count is 1

But if you are not specific enough, it will show just general info:

gw#sh ip route 172.26.0.0

Routing entry for 172.26.0.0/16, 9 known subnets

Variably subnetted with 2 masks

S 172.26.2.0/24 [1/0] via 10.140.0.20

S 172.26.1.0/24 [1/0] via 10.140.0.20

.

.

.

So the only 100% reliable way is sh run.

Regards,

Milan

[leowchongwei]

thanks guys...