WANT TO CHANGE LAYER2 TO LAYER 3 SWITCH

[ssharfuddin]

we are using cisco 6509 series switches as core switches. and Cisco 4510,4507 series switches as edge switches. all the vlans are created at core switches and propogating to edge switches through VTP. we are using OSPF as routing protocol at core switch for internal routing. till now we are using 4510,4507 switches as layer 2 switches. Since, 4510 & 4507 switches are hign end swithces i want use them as layer 3 switches instead of layer 2.if i change these switches from layer 2 to layer 3 does it make any impact on our network or better to keep them as layer 2 switches.if i change these switches to layer 3 is there any advantage i will have . plz clarify me.

THANKS IN ADVANCE

[Jeff Van Houten]

Routing from the edge to the core is a common Cisco recommendation to try to keep spanning tree reconvergence times as low as possible. Whether or not it makes sense is normally judged by the connectivity between the edge and core, the redundancy of that connectivity, the likelihood of a disruption to one of the paths between the edge and he core, the criticality of the data on the network, whether or not arp is consuming sizable bandwidth on your upstream links, and what routing protocol you use. Certainly eigrp is preferred over Ospf in this scenario because convergence is much faster. Simply wanting to turn on edge routing because it's available is not a good enough justification. You need some network maps and some traffic studies before the question can be answered.

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[Joseph W. Doherty]

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Posting

You're written core switches (i.e. plural).  If you have 4500 switches with link to multiple upstream switches, L3 can lend itself to load balancing across the uplinks and faster convergence than STP.

[Maher Shaban]

That Solution is possible and perfect in only one sitiuation. if you have only one Vlan per Switch.

but if you have more than one Vlan on the Switch that is gonna be fuzzy implementing that.

and also if you have voice vlans in your network. the solution will be impossible. I worked on that for at least 2 Weeks, with no solution.