Unanswered Question
Sep 4th, 2009

Dear All.

We need your advice and help on the given diagram and the query.

•L2 Distribution Switch 1 and L2 Distribution Switch 2 will be configured with VRRP for the Redundancy.

•L2 Edge Switches connected to each L2 Distribution Switch with one uplink each. So one will be in forwarding mode and one will be in blocking mode.

•STP will be running on each Switch.

•Default Vlan configured on Each L2 Switch.


1. Can we configured the loopback IP address on router so Fa0/0 and fa0/1 will work with same IP Address. As this IP address will be the gateway to all users connected to Edge Switches.

2.If only One L2 Edge Switch Link connected to L2 Master Distribution Switch Fail, Does the Data will flow through the L2 Second Distribution Switch? As the Master Distribution Switch is Still Working and transferring data of other edge Switch.

3. Can we connect 11 L2 Edge Switches to each L2 Distribution Switch? Only Default Vlan is configured.



I have this problem too.
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mattwilsonuk Fri, 09/04/2009 - 01:41

Could create SVI on router and assign fa0/0 + fa0/1 in the vlan.

Could use ip unnumbered for your loopback address on these interfaces but you will need to create ACL's to prevent loops

Why dont you use your vrrp address as the default gateway?


santosh-khargotre Fri, 09/04/2009 - 02:47

SVI Mean Single Vlan Interface ? can u guide how to config.

can we configured vrrp on L2 switches ?


yagnesh_tel Fri, 09/04/2009 - 05:31


What kind of router you are using? Only Router having integrated switch can support creating SVI. If your router dont support SVI, I would put both router interfaces in a bridge group and then configure a BVI interface for it


Also as you said all your L-2 edge and distribution switches are running STP, STP will be able to manage your fail over so there is no need for VRRP here.

Coming to your last question, it depends on amount of traffic your distribution switches need to handle. If they can handle expected traffic and have enough ports to connect all your edge switches, you won't have any issue.

santosh-khargotre Sat, 09/05/2009 - 02:11

hi yagnesh.

Thanks for giving this detials hope this would solve my problem.

I would like to know does this feature supported by 2811 router.



yagnesh_tel Sat, 09/05/2009 - 04:19

Although 2811 has option of 16-port switching module,I think you are running with just two default routed ports. To confirm this, you can try creating SVI interface with command 'interface vlan 10' and you will see that it won't let you do that.

So in that case go with Bridging option.


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