Force VLAN up/up

mattrgee

Hi all,

Is it possible to force a vlan into an up/up state? All 24 ports of the switch are assigned to the vlan but nothing is connected, I could connect something to one of the ports but the switch is at a remote site.

I did create a loopback interface but there were switchport options avaliable.

Thanks.

networker050184

If you are trying to force an SVI to stay up you can use the "no autostate" command under the interface. This will cause the SVI to remain up/up regardless of the other port states.

mattrgee

Excellent, thanks.

mzinz

networker050184 wrote: »

If you are trying to force an SVI to stay up you can use the "no autostate" command under the interface. This will cause the SVI to remain up/up regardless of the other port states.

Never knew that, very cool.

CGN_Spec

Good Info!

cisco_trooper

networker050184 wrote: »

If you are trying to force an SVI to stay up you can use the "no autostate" command under the interface. This will cause the SVI to remain up/up regardless of the other port states.

Hah. I love it. Enough said.

bmauro

Is this a feature in "new" IOS?


I just unsuccessfully tried this on a 3750 running 12.2(25)SEE1 and a 2950 running 12.1(22)EA12.

"Autostate" was not a valid command.

I know on routers you can issue the "no keepalive" command on the interface which will also place a interface in an "up/up" state regardless of physical connection.

kryolla

spanning tree needs to be forwarding in order for the SVI to come up with the no autostate command it just bypasses this check but I dont see why you would want the SVI to be up with no ports attached to it potentially black hole traffic if the SVI is advertised

networker050184

kryolla wrote: »

spanning tree needs to be forwarding in order for the SVI to come up with the no autostate command it just bypasses this check but I dont see why you would want the SVI to be up with no ports attached to it potentially black hole traffic if the SVI is advertised

I agree. I don't really see the need for it, just something I ran across. I guess you could use it for connectivity checks if all you have are routed ports up. You could just as easily use a loopback though. No reason I can think of to use this in production.

rakem

does it reply to pings if you use the no autostate command?