2950 VLAN

cmadiam82 · ‎11-13-2007

Hi Guys!

Why does the other VLAN on my catalyst 2950 switch turns to administratively down when i try to up the other vlan. Example: i issue the command no shut on vlan 1 then my vlan 2 will turn to administratively down. same as vlan 3. i configured all the vlans to have different subnets. can someone please help me.

Im trying to use Router on a stick config. Do i need to put ip address on each vlan or i will just create vlan then configure a trunk port for my router on a stick?

tnx in advance....

glen.grant · ‎11-13-2007

The 2950 is a layer 2 switch only . You can only have 1 SVI up at a time . The only thing the ip address is for is to manage the switch and nothing else , the 2950 has no routing functionality. you need a separate router or l2/3 switch to be able to route between vlans . If you have a separate router capable of trunking then you just create the layer 2 vlans on the 2950 (not layer 3 SVI interface) and trunk the uplink to the router to route your vlans .

cmadiam82 · ‎11-13-2007

Tnx Glen for your fast reply. I will try it again and give you feedback.

Richard Burts · ‎11-13-2007

Chester

I think that is might be helpful to clarify the difference between having multiple VLANs (which the layer 2 switch can do) and having multiple VLAN interfaces (which the layer 2 switch can not do).

A VLAN is a layer 2 concept and the switch can configure multiple VLANs. Each VLAN is a separate layer 2 broadcast domain. The switch maintains a MAC address forwarding table (or CAM table) for each VLAN and can forward from any device in the VLAN to any device in the VLAN.

A VLAN interface is a layer 3 concept. A layer 2 switch can have only 1 active VLAN interface. The real purpose of the VLAN interface is to provide remote management to the switch. If you configure more than 1 VLAN interface on a layer 2 switch then only 1 can be active at a time and any other configured VLAN interface will be administratively down.

HTH

Rick

HTH

Rick

cmadiam82 · ‎11-13-2007

Tnx Rick! I will always keep that in mind. :)

sarfaraz1981 · ‎11-13-2007

i agree with glen.grant and u can have only layer 2 vlans on cisco 2950 switch, dont assign ip addrees to other vlan apart from mangement vlan.