Routing VLAN traffic

beast_gts · ‎04-10-2006

Is it possible to route VLAN traffic?

We have two buildings, each with several Catalyst 2950s and a 2651 router hosting several VLANS.

Can we connect the 2651s together and expand the VLANs into the other building?

globalnettech · ‎04-10-2006

Hello,

in addition to Mahmood's post, it is not recommended to have VLAN's span Layer 3 (routed) networks. Your performance will suffer because of the amount of broadcast traffic going over the routed interfaces. It would be a better idea to have a fiber run between both your buildings, and connect e.g. two of your 2950 switches, one in each building, with fiber GBIC's, in order to expand the range of your VLAN's.

Regards,

GNT

beast_gts · ‎04-16-2006

Hi GNT.

That was my first idea, but it means running fiber. There's an existing serial link.

mahmoodmkl · ‎04-16-2006

HI

Can u give info about how these two buildings are connected to each-other.and as far routing in concerned u can configure sub-interfaces under u r physical inteface on u r router.Are this 2950's connected in 2651,if they how r u r vlans spread.r u using any sort of vtp.if u r 2950's are connected to 2651 then u can go for sub-interfaces per vlan.

for example if u r having 3 vlans then u can configure the the physical interface on u r router as

interface f0/0.1

encapsulation dot1q 1

ip address 192.168.1.1 255.255.255.0

and so on

Thanks

Mahmood

beast_gts · ‎04-16-2006

There's a serial line between the two buildings.

In each building the 2950s are connected to the 2651. Sub-interfaces are configured for inter-VLAN routing in each building. VTP is not used.

What I want to do is expand an existing VLAN from building 1 to building 2 (reorganisation). Is this possible?

mahmoodmkl · ‎04-16-2006

HI

I think u can expand u r vlans but i think u r provider should support it altough it is not recommended to this.

Thanks

Mahmood

beast_gts · ‎04-16-2006

So the best solution would be to not bother with the existing serial link but to install a new fiber link and retire one of the routers?

globalnettech · ‎04-16-2006

Hello Geoff,

that would indeed be the best, and actually the only feasible, option. Otherwise, keep the VLAN´s separated to each building and use your routers for connectivity.

Regards,

GNT

ratheeshrg · ‎04-17-2006

Please let me know why you want to expand the VLANs between buildings?

Whatever be the reason it is very much possible to use the existing router itself to implement the solution.