Access, Distribution, Core question

fightclub34

Ok i keep hearing that the core should just do switching. If you have vlans that are terminating at the distribution layers with SVI's how exactly does the data flow from the distribution to the core. Is it layer 3 interfaces or do you create SVI's on the core to route in the distribution layer vlans. When i hear routed port to me that means layer 3 and routing not switching. If anyone has an example of how the core layer is suppose to be setup that would be awesome

bighornsheep

It could be 10gig ports, atm interfaces, or many other high speed interfaces.

Typically, you keep the core as a single layer 2 domain without another router to keep things at high transmission speeds.

tech-airman

fightclub34 wrote: »

Ok i keep hearing that the core should just do switching. If you have vlans that are terminating at the distribution layers with SVI's how exactly does the data flow from the distribution to the core. Is it layer 3 interfaces or do you create SVI's on the core to route in the distribution layer vlans. When i hear routed port to me that means layer 3 and routing not switching. If anyone has an example of how the core layer is suppose to be setup that would be awesome

fightclub34,

Who is telling you "...the core should just do switching...?"

fightclub34

I have been studying for bcmsn and both video sets i watched and the book says the core should be used for fast switching as much as possible.

Forsaken_GA

fightclub34 wrote: »

I have been studying for bcmsn and both video sets i watched and the book says the core should be used for fast switching as much as possible.

The basic premise is that you want to keep as much slowdown out of the core as possible. It shouldn't concern itself with things like policy, so don't apply access lists, do any packet filtering, or route between vlans with your core routers. All of that should be taken care of at the distribution layer so that the core can just move packets around as quickly as possible