How to UP vlan SVIs with no ports connected ?

[adventurer]

Hi, i have a test scenario with a single Cisco 3550. It has vlans 1,10,20,30 with respective L3 SVIs and there are interfaces assigned to every vlan. However only 1 host is connected to vlan 1. Result is vlan 1 SVI is UP but vlan 10,20,30 SVIs are DOWN. Is there a way to UP the rest of the SVIs without physically connecting more devices ?

Regards.

[johnsos]

Best I know is assign one port to each of the SVI's and then put a looping plug into these ports. No device needed other than the plug. Too bad that you can't just put no keepalive on the FastE ports and make the L3 interface comeup. Switch is a bit different. Pins 1&3 looped back to 3&6. You already probably knew this just wanted to add it.

Steve.

[ankurbhasin]

Hi joelau007,

You can also configure any port as a trunk port and it will bring all the virtual interfaces up.

HTH

Ankur

[adventurer]

Hi,

Will it work in this case ? Since i have only 1x 3550, if a switchport mode trunk is configured on Gi0/1, physical interface will also be in a down state.

Regards.

[ankurbhasin]

Hi,

No it will not work like that port need to be up on which you configure a trunk.

Can we try something...

Configure 2 ports as trunk on same switch and using a single cable connect 2 ports together like a loop and lets c what happens.

Regards,

Ankur

[johnsos]

Let us know how STP deals with this loop?

[adventurer]

I'll post a reply to this thread after i try it. It's my customer's equipment.

Regards.