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New Member

Layer 3 switch routing

How can I set up routing on two layer three switches so that a device in between them only sees communication from two mac addresses?

Network Traffic -> Switch thats routing --Trunk->  Switch that limits mac address communication <--trunk- Switch thats routing <-- Other Network

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4 REPLIES
Cisco Employee

Layer 3 switch routing

Scott,

What is the device you have in between?. If it is L2 device, you can configure some SVI (or even the physical interface) of the L3 switches with IP from same subnet and enable any routing protocol.

Network1------(L3SW1)(Intf1)--------(Intf1)(L2SW)(Intf2)-------(Intf1)(L3SW2)----Network2

This way, any traffic from Network1 on reaching L3SW1 will be performed with L3 lookup, encapsulate with Source MAC as Intf1 of L3SW1, Destination MAC as Intf1 of L3SW2 and send across. Similarly traffic from Network2 to Network1 will use the reverse MAC.

So ideally L2SW will only see2 MACs (Intf1 of L3SW1 and Intf1 of L3SW2.

HTH,

Nagendra

New Member

Re: Layer 3 switch routing

I do not know what the middle piece of equipment is. It's hosted by AT&T

How would I encapsulate with the source mac and vice versa?

New Member

Re: Layer 3 switch routing

So I think I may have it.

If I have vlan 1 at both locations and I set my trunk ports as switchport trunk encapsulation dot1q, allow vlan 200 on the trunk ports and have intervlan routing setup on both locations switches the packets should be able to flow through and the middle device would only see the switches on vlan 200 running the encasulation.

Correct? maybe? wayyyyy off? =) Thanks for all the help so far.

New Member

Re: Layer 3 switch routing

yes Scott,

you are going to need create SVI to be able to route. inter and intra vlans.

hope that helps

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