Behavior of interface VLAN related to physical port

[ccnaluna93]

Interface VLAN got UP when its vlan was assigned to a physical port, but then I removed that VLAN from that physical port and the interface VLAN was still UP, is this right?

I ask this because I'm testing on Packet Tracer and I would like to know if if this behavior happens with real devices as well.

I would appreciate your help!

[Reza Sharifi]

I ask this because I'm testing on Packet Tracer and I would like to know if if this behavior happens with real devices as well.

That may be the behavior of the PT, because with real devices if there is no physical port connected to the VLAN, the vlan interface will go down unless the vlan is added to the trunk link.

HTH

[ccnaluna93]

Yes, actually I had to asociate the VLAN to a physical port in order to get my interface VLAN up, but after a while I removed the VLAN from that physical port and the interface VLAN was still up even if the was not physical port anymore.

Then as you said, in real devices, the interface VLAN will go down after we remove the VLAN from that physical port

[Giuseppe Larosa · Accepted solution]

Hello @ccnaluna93 ,

in real world an SVI interface VLAN can be kept up/up by a trunk port that allows all Vlans.

The tracking of L2 ports is called autostate an SVI interface is up/up if at least one L2 port either an access port or a trunk port is up/up and in STP forwarding state for the corresponding L2 VLAN.

Hope to help

Giuseppe