L3 switch - router

[bapatsubodh]

Hi,

In a very high level view ( or root level view perhaps) how does the packet forwarding by L3 switch is different that router?

What is the selection criteria for the device selection L3 switch or router?

Thanks

Subodh

[Mohamed Sobair]

Hi,

The router performs routing lookup to determinw the next hop ip address and Link layer address with the outgoing interface to forward the packet to the destination.

L3 Switch performs this lookup at the first time, once the Source and Destination Mac is verified, the L3 Switch performs switching at layer-3, it Simply preserves/copies the TTL value from the IP header and perform switching using the Source and Destination Mac at layer-3.

HTH,

Mohamed