Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

VLAN int to be down when no physical interfaces are up

Very simple question:

I have a core switch. I want a specific VLAN IP interface to be declared as "down" when no physical interfaces using it are available (access ports or trunks).

I don't want this core switch to propagate a route to which is has no real connectivity.

So far, I can see that if the vlan exists in the vlan database, and an IP address was assigned, this is enough to make its line protocol be "up" (when executing "show int vlan x").

I want it to look like:

switch#sho int vlan X

VlanX is up, line protocol is down

Do you know if a vlan lan protocol state can be associated to a physical interface lan protocol state?

This may be related to shutting down the vlan internally in the switch. Don't know how to make this happen automatically.

Thanks

2 REPLIES
Purple

Re: VLAN int to be down when no physical interfaces are up

It should not be up if the vlan is not being used as a access port or allowed across a trunk . I would take a closer look it is probably up somewhere or the vlan is allowed across a ctive trunk link .

New Member

Re: VLAN int to be down when no physical interfaces are up

Thanks Glen

There is a trunk allowing this VLAN. Nevertheless, the trunk is down. The VLAN is still up. Strange, don't you think?

This is a 6509 running 12.2

265
Views
0
Helpful
2
Replies