Hello, I am doing some troubleshooting on a Cisco 7606 in regards to high CPU (between 50 and 75%). When I do a "show proc cpu" I do not show any processes that are using up the CPU. The one thing we are doing differently on this router is terminating about 4 GRE tunnels. In addition when I do a "show mls stats" I am showing the router is currently processing about 500,000 PPS:
#show mls statistics Statistics for Earl in Module 1 L2 Forwarding Engine Total packets Switched : 943744507055 L3 Forwarding Engine Total Packets L3 Switched : 943744507055 @ 520113 pps Total Packets Bridged : 159661113984 Total Packets FIB Switched : 783029776276 Total Packets ACL Routed : 0 Total Packets Netflow Switched : 0 Total Mcast Packets Switched/Routed : 884048717 Total ip packets with TOS changed : 0 Total ip packets with COS changed : 0 Total non ip packets COS changed : 0 Total packets dropped by ACL : 779576 Total packets dropped by Policing : 0 Total Unicast RPF failed packets : 0 Errors MAC/IP length inconsistencies : 1 Short IP packets received : 0 IP header checksum errors : 0 MAC/IPX length inconsistencies : 0 Short IPX packets received : 0 Total packets L3 Switched by all Modules: 943744507055 @ 520113 PPS I recently read a Cisco forum document that stated GRE tunnels can push up CPU if they "share the same source interface" and suggestion was to use 1 loopback interface per GRE tunnel: https://supportforums.cisco.com/discussion/10920621/high-cpu-utilization-7600-rsp720-and-gre-tunnel I have performed re-configuration of our GRE tunnels to use a Loopback interface as source however I am still seeing CPU in range of 50-75%. Should GRE tunnels cause this much of a CPU increase? I guess my other question is in relation to software switched versus hardware switched. I am showing that my GRE interfaces are using FastCEF so I would expect performance not to be an issue however the GRE tunnel (and Loopback) are indeed software interfaces so does CEF even come into play regarding GRE tunnel interfaces? #show mod Mod Ports Card Type Model Serial No. --- ----- -------------------------------------- ------------------ ----------- 1 2 Catalyst 6000 supervisor 2 (Active) WS-X6K-SUP2-2GE SAL08486LSL 3 8 8 port 1000mb GBIC Enhanced QoS WS-X6408A-GBIC SAL050630Y0 Mod MAC addresses Hw Fw Sw Status --- ---------------------------------- ------ ------------ ------------ ------- 1 0012.0150.4ad0 to 0012.0150.4ad1 5.1 7.1(1) 12.1(27b)E1 Ok 3 0001.9724.0e54 to 0001.9724.0e5b 1.3 5.4(2) 8.5(0.23)COS Ok Mod Sub-Module Model Serial Hw Status --- --------------------------- --------------- --------------- ------- ------- 1 Policy Feature Card 2 WS-F6K-PFC2 SAL084764AX 3.5 Ok 1 Cat6k MSFC 2 daughterboard WS-F6K-MSFC2 SAL08517DM7 2.8 Ok Mod Online Diag Status --- ------------------- 1 Pass 3 Pass I have been referring to this document quite a bit to reference PPS: http://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf With the MSFC2/PFC2 I would expect to have a capacity of 15/30 million PPS on this 7606 however I suspicion I am hitting bottleneck of a software switched interface (500,000 for software-switched CEF). Anyone have any pointers or tips? I know many will be laughing that MSFC2/PFC2 is still in play but it is what it is. Should I consider offloading these tunnels to another device? The nature of the high PPS traffic is RTP/VOIP (so many PPS of smaller packets). Thanks, Rich _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
