-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Arda Balkanay wrote: > Hi > i have a problem about high cpu usage on a 7206 VXR NPE-G1 because of > process switching on a multilink ppp interface. > > I have two E1 interfaces between 7206 and 3845 (below MTP-C72-02 indicates > 7206 and ADN-C38-01 indicates 3845). > I've bundled these two E1 interfaces. And when the amount of traffic rised > CPU usage also increased about 15 percent more. > "show proc cpu" output points increase at the processes of ip input and tag > input. > MTP-C72-02#sh proc cpu sorted > CPU utilization for five seconds: 78%/64%; one minute: 79%; five minutes: > 81% > PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process > 68 39242000 258183793 151 8.92% 8.20% 8.40% 0 IP > Input > 109 25093708 119681214 209 6.88% 7.37% 7.79% 0 Tag Input > > > When i looked at the switching status of the interface i saw that 7206 is > using process switching while 3845 uses fast switchig (especially for mpls) > MTP-C72-02#sh inter mul 1 switching > Multilink1 Maltepe - Adana MLPPP > Throttle count 0 > Drops RP 752707 SP 0 > SPD Flushes Fast 0 SSE 0 > SPD Aggress Fast 0 > SPD Priority Inputs 259 Drops 0 > > Protocol IP > Switching path Pkts In Chars In Pkts Out Chars Out > Process 50148189 395174672 261949 26235771 > Cache misses 0 - - - > Fast 1325 105874 12194 724886 > Auton/SSE 0 0 0 0 > > Protocol Tag > Switching path Pkts In Chars In Pkts Out Chars Out > Process 79390997 3601460527 5116 538398 > Cache misses 0 - - - > Fast 0 0 87354606 4071850482 > Auton/SSE 0 0 0 0 > > > ADN-C38-01#sh inter mu 1 switching > Multilink1 Adana - Maltepe MLPPP > Throttle count 0 > Drops RP 0 SP 0 > SPD Flushes Fast 0 SSE 0 > SPD Aggress Fast 0 > SPD Priority Inputs 242 Drops 0 > > Protocol IP > Switching path Pkts In Chars In Pkts Out Chars Out > Process 32394 2110804 17595 1260300 > Cache misses 0 - - - > Fast 559376 60411948 154 8439 > Auton/SSE 0 0 0 0 > > Protocol Tag > Switching path Pkts In Chars In Pkts Out Chars Out > Process 7106 398899 10784 539203 > Cache misses 0 - - - > Fast 87130476 3140243335 80454345 488241675 > Auton/SSE 0 0 0 0 > > > When i checked "show ip interface" output i can see that fast swithing is > enabled but i didn't understand why 7206 uses process switching while 3845 > uses fast > swithcing with the same multilink interface configuration. ip interface > output is as follows: > > MTP-C72-02#sh ip int mu 1 > Multilink1 is up, line protocol is up > ... > IP fast switching is enabled > IP fast switching on the same interface is enabled > IP Flow switching is disabled > IP CEF switching is enabled > IP CEF Fast switching turbo vector > IP Null turbo vector > IP multicast fast switching is enabled > IP multicast distributed fast switching is disabled > IP route-cache flags are Fast, CEF > ... > MTP-C72-02# > > ADN-C38-01#sh ip int mu 1 > Multilink1 is up, line protocol is up > ... > IP fast switching is enabled > IP fast switching on the same interface is enabled > IP Flow switching is disabled > IP CEF switching is enabled > IP CEF Fast switching turbo vector > IP multicast fast switching is enabled > IP multicast distributed fast switching is disabled > IP route-cache flags are Fast, CEF > ... > ADN-C38-01# > 7206 uses ios c7200-jk9s-mz.123-14.T3.bin and 3845 uses > c3845-spservicesk9-mz.124-8b.bin > > > Do you have any idea about this situation ? > >
Take a look at the output of "show cef interface" which will tell you why packets would be dropped into a slower switching path: Dialer1 is up (if_number 6) Corresponding hwidb fast_if_number 6 Corresponding hwidb firstsw->if_number 6 Internet address is 172.25.1.1/24 ICMP redirects are never sent Per packet load-sharing is disabled IP unicast RPF check is disabled Inbound access list is not set Outbound access list is not set IP policy routing is disabled BGP based policy accounting on input is disabled BGP based policy accounting on output is disabled Interface is marked as point to point interface IPv4 packets switched to this interface are dropped to the next slow path: Dialer ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Hardware idb is Dialer1 Fast switching type 15, interface type 96 IP CEF switching enabled IP CEF switching turbo vector IP prefix lookup IPv4 mtrie 8-8-8-8 optimized Input fast flags 0x0, Output fast flags 0x0 ifindex 5(5) Slot -1 Slot unit -1 VC -1 - -- ========= bep -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFG1agIE1XcgMgrtyYRAi6QAJ0VZo1dbjmwdvk8lSFj7TqzzfjnOwCfYjNs MXUi5c2Q+MAkn+vzJtWzcWg= =sRhw -----END PGP SIGNATURE----- _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/