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.
Just a sanity check before I open a TAC case. Brief test output below was obtained using a pair of 3550 switches: Without GRE: ------------------------------------------ C:\>iperf -f m -s -p 333 ------------------------------------------------------------ Server listening on TCP port 333 TCP window size: 0.01 MByte (default) ------------------------------------------------------------ [1752] local 172.16.0.2 port 333 connected with 172.16.1.2 port 1058 [ ID] Interval Transfer Bandwidth [1752] 0.0-15.0 sec 165 MBytes 92.4 Mbits/sec With GRE: ------------------------------------------ C:\>iperf -f m -s -p 333 ------------------------------------------------------------ Server listening on TCP port 333 TCP window size: 0.01 MByte (default) ------------------------------------------------------------ [1752] local 172.16.0.2 port 333 connected with 172.16.1.2 port 1061 [ ID] Interval Transfer Bandwidth [1752] 0.0-15.0 sec 23.7 MBytes 13.2 Mbits/sec ------------------------------------------------------------ Thanks much. Vijay Ramcharan _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
