Routed vs. Routing protocols

Gat0rvean

This is a fairly simple topic, but I'm gonna post it anyway so that it sticks in my head!

Are RoutED protocols confined to the network layer? Or is pretty much any protocol that is _not_ a routING protocol and can be forwarded by a router (i.e. not netbuei)? a routed protocol?

NetworkVeteran

Let's begin with a definition--

Routing, Jennifer Rexford wrote:

Routing: control plane
Computing paths the packets will follow
Routers talking amongst themselves
Individual router creating a forwarding table

Are RoutED protocols confined to the network layer?

Yes, since the above definition included the term packet. Realize that definitions are a map and that maps sometimes fail to perfectly reflect reality. PNNI and TRILL challenge the standard definitions.

Or is pretty much any protocol that is _not_ a routING protocol and can be forwarded by a router (i.e. not netbuei)?

This is true if we're considering a theoretical router and false if we're considering a real one. I say that because many real routers will perform Integrated Routing and Bridging (IRB)--they can be asked to forward L2 frames!