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Enabling layer 3 switching in the wiring closet

Cisco' s position at the access layer has been layer 2, using uplinkfast and backbonefast. Extreme and Foundry are pushing L3 at the edge in their designs for load balancing, QOS and fault tolerance. ( resulting in a more complex network)

Has anyone deployed layer 3 ( OSPF) at the access layer using the Cisco 3550s in a campus environment? ( 6500s collapsed core)

I appeciate feedback on the L3 impact/performance for a high-bandwidth mission critical network.





Re: Enabling layer 3 switching in the wiring closet

Hi Hugh,

According to the Hierarchical Network design,

The access layer is where the users are connected into the network and the devices need to have scalable uplinks to higher layers.

The Distribution layer is designed to provide the connection between the access and the core layers and handle layer 3.

However if you would like to deploy a Routing protocol at the access layer, you would have to keep in mind the potential impact on the network and also the capability of the device to handle High Layer 3 throughput for routing packets and also mission critical traffic.

New Member

Re: Enabling layer 3 switching in the wiring closet

Thx mchin,

The goal for enabling layer 3 in the access is to have load balancing to the distribution/core.

Zero downtime on uplink failures is a requirement, that even uplinkfast is not enough. The performance hit of OSPF is somthing i was curious about.



New Member

Re: Enabling layer 3 switching in the wiring closet

I agree with you that load balancing at Access layer using L3 services with the added benefit of zero down time (great idea here) but somehow I'm not sure if the 3550 is capable of switching packets fast enough at the L3. From memory, 3550 is not capable of doing MLS which I think will impact the performance of the network. Please let me know otherwise at

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