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New Member

Collapsed Core / Distribution VLAN Config

Hi Guys,

I was wondering if you could provide me with some insight.

If I have 2 L3 devices in my collapsed core and distribution layer, how do I go about configuring VLANS?


Currently I have 2 Core/Dist Switches both running L3 and 5 Access Switches

I've configured STP and VTP accross the campus and all is working well.

Now, a sh run from core1 shows vlan information including ip address of interface for the vlan etc, but core2 doesn't, it's aware of the VLANs due to VTP but doesn't display any interface information.

If Core1 was to fail, how does my network know how to route? 

is this design recommended?



New Member

Make one of the collapsed

The following is only my opinion:

VTP mode transparent across all devices. Unless you are doing some sort of 802.1x authentication I don't see a need, just headaches.

Make one of the collapsed core members the STP root via the spanning tree prior 0 command for all vlans. Set the other member as a backup with the spanning tree prior 4096 or some other small value for all vlans.

Create a trunk between the collapsed core members trunking all vlans.

Create a trunk from each access switch to each collapsed core member and trunk the appropriate vlans, or all.

Create your layer 3 interfaces for the vlans on the collapsed core members and set up redundancy via HSRP or VRRP. 

New Member

Hi,we are using 2 4150r in


we are using 2 4150r in the collapsed core, which doesn't support HSRP as far as i can tell HSRP isn't supported by this device :(


have you got any other suggestions?



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