Solved: 3750 null0

Danilo Dy · ‎03-29-2007

Hi,

I created a null0 interface in 3750, I can't see the interface in the "sh run" but I'm able to route RFC 1918 to it.

Is this normal?

TIA

Jon Marshall · ‎03-30-2007

Hi

I believe it is. I have just tried creating a null0 interface in our lab on

3550

3560

6509

2621

7206VXR

None of them showed up in config. i believe this is because it is a pseudo-interface similar to /dev/null in unix. You can always add routes that point to Null0 and the IOS will do the right thing and blackhole them.

You can also do a limited amount of config on the null0 interface but it won't take an ip address etc.

HTH

Jon

View solution in original post

Jon Marshall · ‎03-30-2007

Hi

I believe it is. I have just tried creating a null0 interface in our lab on

3550

3560

6509

2621

7206VXR

None of them showed up in config. i believe this is because it is a pseudo-interface similar to /dev/null in unix. You can always add routes that point to Null0 and the IOS will do the right thing and blackhole them.

You can also do a limited amount of config on the null0 interface but it won't take an ip address etc.

HTH

Jon

Danilo Dy · ‎03-30-2007

Hi Jon,

Thanks for confirmation.

In 7500 series routers with IOS 12.1, the null0 intrerface is visible in the config.

Regards,

Dandy