HP 2920-48 port hardware routing?

[Jonathan Tripathy]

Hey All

We have just purchased an HP Procurve 2920-48 (non-POE) switch, and are making use of the L3 routing functions.

My question is, is the routing done in hardware or software? What is the max routing performance I could expect to see? It is "wire-speed"?

I read somewhere for another older HP L3 product that only about 200 "host routes" were supported in hardware routing, after that routing done in software. What are "host-routes" in this case? For example, in my case, I have a single VLAN with about 500 servers on it. This VLAN does have multiple subnets on it (and accordingly, the VLAN on the switch has one IP per subnet). Beyond that, the only static route on the switch is for 0.0.0.0 to go to our provider's default gateway. Assuming all servers were sending traffic out to the internet, does this mean the switch would start to do routing in software?

Your help is appreciated

Thanks

Jonny

[Michael Patmon]

Hello.  To your first two questions: routing is done in hardware and should be wire speed. 

A host route just means an individual IPv4/IPv6 address, or a /32 IPv4 route or /128 IPv6 route.  Some of the really old routers would have to program a host route in hardware for a particular destination.  All the newer platforms, including 2920, use prefix based routing.  In other words you program one route in hardware for the entire network/mask.  A next hop route pointing to 10.0.0.0/24 is one hardware route.  Your 0.0.0.0/0 is one hardware route.

Local hosts, that is hosts residing on a connected network, will program a host route in hardware.  You should be able to do at least 10k there.  That's mainly a software limitation on the number of ARP entries we can learn. 

So what you're doing should work just fine.