Thanks for the clarifications and feedback received from all. GRE on 3750 = software switched with no candy and tastes bad :-( GRE on 3845 = software switched but with candy so it's more palatable :-) Vijay Ramcharan -----Original Message----- From: Adrian Chadd [mailto:[email protected]] Sent: March 23, 2009 12:33 To: Ramcharan, Vijay A Cc: [email protected] Subject: Re: [c-nsp] GRE throughput on 3750G
On Mon, Mar 23, 2009, Ramcharan, Vijay A wrote: > All, > I'm just looking for confirmation that GRE on the 3750G is done in > software with the resulting low throughput (~20Mbps with iperf across > GRE tunnel on 3750G). All testing and reading that I've done indicates > that the hardware on the 3750 is not especially built for > "router-specific" features like GRE. A "show int stats" shows that all > packets on the tunnel interface in a pair of 3750G switches is process > switched. The same command on a 3845 shows the majority of the traffic > is hardware switched/forwarded. Uhm, unless the 3845 has some sugar I completely missed, its also software forwarding it - its just that the 3845 IOS is 'optimised' for software forwarding. The 3845 probably has much higher bus bandwidth between the CPU and network interfaces. The 3750(G) also probably has a much slower CPU. > Just a sanity check before I open a TAC case. I bet the answer will be "Don't do GRE on 3750G, its unsupported." HTH, Adrian ______________________________________________________________________ This e-mail has been scanned by Verizon Managed Email Content Service, using Skeptic(tm) technology powered by MessageLabs. For more information on Verizon Managed Email Content Service, visit http://www.verizonbusiness.com. ______________________________________________________________________ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
