Contents
Why is VLAN interface up down?
The VLAN interfaces have to fulfill these general conditions to be up/up: The VLAN exists and is in active status on the switch VLAN database. The VLAN interface exists on the switch and is not administratively down. At least one Layer 2 (L2) (access port or trunk) port exists and has a link up on this VLAN.
Why is SVI interface down?
Following are most common cases when troubleshooting SVI in up/down state: Make sure that the VLAN this SVI represents exists in the VLAN database. So, if you are creating an SVI for vlan 10, make sure that you have already created that VLAN. In this case, make sure, that the SVI vlan is allowed through the trunk.
Is up line protocol is down Autostate enabled?
On Cisco switches, after creating a new VLAN, we have noticed that VLAN interface is up however protocol doesn’t come up. This is because of Autostate feature that is implemented on Cisco switches with CatOS and IOS platforms and also activated by deafult.
What is VLAN interface state?
A VLAN interface is always up, but its line protocol state tracks the state of attached ports: if at least one port is operational, the line protocol of the VLAN interface is up, otherwise it’s down.
How do I know if a VLAN is down?
Use the show vlan command to verify your VLAN configuration. This command displays all switchports and their associated VLAN as well as the VLAN status and some extra parameters that relate to Token Ring and FDDI trunks. You can use the show vlan id [vlan#] command to see information about a particular VLAN.
How are VLANs configured?
Generally three or four things must be configured on VLAN capable switches:
- Add/define the VLANs. Most switches have a means of defining a list of configured VLANs, and they must be added before they can be configured on any ports.
- Configure the trunk port.
- Configure the access ports.
- Configure the Port VLAN ID (PVID)
How to tell if VLAN is down, line protocol is down?
To bring the newly created SVI interfaces up. you need to assign atleast one port to the VLAN you have created. once you do this just see what you get when you type show command. With no ports assigned to a VLAN, the line protocol of the VLAN interface will be down. >>sh ip int brief.
Is the vlan interface in a forwarding state?
* VLAN interface exists and is not administratively down. * At least one L2 (access port or trunk) port exists and has a link up on this VLAN. In your case, since you do not add any layer 2 access port to the VLAN, you need to check whether the trunk port is in Forwarding state for the VLAN.
Is the vlan interface down on Layer 2 switches?
I believe that layer 2 switches will have only one UP/UP SVI for management, while any other created SVI will be in the administratively down status (at least this was the case with my 2900XL), but since this SVI is down/down then i believe that as i’ve suggested the VLAN is not configured on the switch.
Can a switch shut down a VLAN connection?
If you don’t have any access ports in the VLAN, and you are not trunking the VLAN across at least two trunk ports then the switch has no possible place it could forward the tagged packets to. Consequently it can shut it down.