SVI Creation Prerequsites

Tobivan_Helden_2 · ‎12-22-2008

Hi,

ISR 2821, IOS packaging is SPServ. Have a pretty but important to me question.

{

(conf)# int ? <!--- want to check is there 'vlan' int is available

... there is no Vlan in the ouput ...

}

What conditions must be met/configured before SVI (switched virtual interface) would be allowable to create ?

Thank you.

mahmoodmkl · ‎12-22-2008

Hi

Make sure that u have vlan created at L2 before u create SVI.

Thanks

Mahmood

Tobivan_Helden_2 · ‎12-23-2008

Is it possible to create L2 vlan on the ISR ?

I always think the undermentioned functionality

{

#conf t

(conf)# vlan

(conf-vlan)# name

}

is only available on switches ?

mahmoodmkl · ‎12-23-2008

Hi

I think i mis-interpret u r question.

I dnot think u can create the L2 vlan on this router.

I assume u r thinking of crreating the sub-interfaces...?

Please elaborate.

Thanks

Mahmood

glen.grant · ‎12-23-2008

That command is there if you happen to install one of the 4,8 or 16 port switchcards into the chassis, then you create the SVI's for that switchcard as you would for any layer 3 switch . Its of little use if you don't have a switchcard installed.

Richard Burts · ‎12-23-2008

Tobivan

Perhaps I am not clear about what you are attempting to accomplish. If your interpretation of SVI is specificcally to create a "VLAN" interface then Glen is correct that the only way to create a VLAN interface on the 2821 router is to have a switch module installed. But another possible interpretation of SVI is the ability to communicate with VLANs running on a switch. In that case you can configure the Ethernet interface(s) for trunking by configuring subinterfaces and assigning VLANs to the subinterfaces. It might look something like:

interface gig0/0.15

encapsulation dot1q 15

ip address x.x.x.x

interface gig0/0.22

encapsulation dot1q 22

ip address y.y.y.y

If I have not correctly understood what you are trying to accomplish then perhaps you can clarify for me.

HTH

Rick

HTH

Rick

glen.grant · ‎12-23-2008

Ric is certainly correct if all you want to do is to route multiple subnets across a link (router on a stick) then you would just use subinterfaces to accomplish that .

http://www.cisco.com/en/US/tech/tk389/tk815/technologies_configuration_example09186a00800949fd.shtml