interface

[dkblee]

Hi!

What's the purpose of setting an ip in a vlan interface?(eg. int vlan 10)

What could be the possible reason if the vlan interface is down even after issueing "no shut"?

Thanks.

[spremkumar]

Hi

SVI (Vlan interfaces with ip assigned) in Layer 2 switches are configured for management purpose.

Using the ip you can logon to the switch and carry out the required/desired activities.

also used to monitor the switch ports/trafic being handled by the switch..

If you are seeing an vlan interface still down better assign the vlan under a port which is active.

Also enable the vlan in the vlan database..

If you are trying to configure more than one SVI which you wont be able to do in a L2 switch you will ofcourse see the existing vlan going down automatically.

regds

[dkblee]

Hi!

I'm using an 2950 switch, you are saying that the vlan interface will only be up if i have a vlan assigned to a port and connect that port to a PC?

The 2950 switch still allow me to configure the vlan interface with IP. Just that it is always "shutdown". I think there must be a purpose if it accept the command right?

Pls advise again. Thanks.

[glen.grant]

Is it shutdown or is it down/down ? If it is admin down then you have to "no shut" the SVI (int vlan xx) . The interface will only be up/up if you have an active port in that vlan whether be a pc or an uplink to a router .. That ip address in the switch is strictly used to manage the switch and is not used for any kind of router or gateway function . Any routing is done by a router or a l2/3 switch .

[icabrera]

Hi, you put an ip address to the switch to be able to manage it via this ip.

Probably it's down because there is another interface vlan x that is up and you can have only one.

Regards

[dkblee]

Hi! I know that vlan1 is for management purposes. How about the custom int vlan eg. vlan 10, 20 etc?

You are saying that i can only have one vlan interface in a 2950 switch? In that case, what's the purpose of the switch accepting other vlan interface? Thanks.

[spremkumar]

Hi

You can have L2 VLANs enabled under vlan database of the switch if its configured under VTP transparent mode ,which you can of course configure on a interface using switchport command and make the interface member of the particular vlan.

But you have the limitation of having only one L3 interface (SVI - VLAN interface with ip address configured) in Layer 2 switch. Cisco 2950 switch is again a Layer 2 switch.

regds

[icabrera]

Yes, you can have only one vlan interface up at the same time.

The switch accept other vlan interfaces to let you decide and configure what is going to be your management vlan, if you cannot define other vlan interfaces you can only have vlan 1 as your management vlan.

Regards

[dkblee]

Hi! Thanks.

What's the command to configure other vlan as the management interface?

[icabrera]

You need only to configure another interface:

interface vlan x

ip add

no shutdown

where x is the management vlan.

Regards

[dkblee]

Hi! I tried that. The newly created vlan interface is always "shutdown" when i issue "sh run". Only the default vlan1 doesn't show "shutdown".

[icabrera · Accepted solution]

Hi, see next url:

http://www.cisco.com/en/US/products/hw/switches/ps628/products_command_reference_chapter09186a0080150b7b.html#wp1021813

It says that when you put "no sh" under the new vlan interface the vlan1 will pass to shutdown state. If itisn't working for you try to erase the configuration and start again, it should work.