Symptom

If attach a service which is not enabled to a interface, and then detach it, this will cause the service at index 0 in wccp cpp client be changed to unconfigured state. This bug may have the following symptoms: 1. The web-cache service works fine, but the counters of it will be incorrect. 2. If web-cache is the only service, a traceback will appear, because wccp cpp client can't find any active descriptor, thus the periodic stats polling fails.(see traceback_decode_1) 3. If then config a new service and make it active, like config service 61 and 62, web-cache service will not work anymore, because service 61 has overwrite the descriptor of web-cache in cpp_client. The packets that should be sent to client of web-cache will be sent to client of service 61 instead. 4. If change the properties of web-cache after step 3, a traceback will appear. (see traceback_2) 5. If remove service web-cache after step 4, with "no ip wccp web-cache" command, a traceback will appear. (see traceback_3) 6. fman-wccp and cpp-client will keep querying and sending stats update continuously, may cause IOSD ipc task high CPU usage.

Conditions

There are 3 cases of WCCP configuration: 1. WCCP service is configured on global & interface level. 2. WCCP service is configured on global level, but not configured on interface level. 3. WCCP service is not configured on global level, but configured on interface level. This issue is only triggered if unconfigure the service on interface in case 3. There is a special case which is less possible to occur can also trigger the issue: 1. WCCP service is configured on global & interface level. 2. Unconfigure the service on global level, and it remain configured on interface level. 3. Reload the router. 4. Unconfigure the service on interface level. In this case, after reload in step 3, It is the same as case 3. If there is no reload operation, every will be fine. commands: Ultra-WCCP1#conf t Ultra-WCCP1(config)#ip wccp web-cache Ultra-WCCP1(config)#interface gigabitEthernet 1.200 Ultra-WCCP1(config-subif)#ip wccp 23 redirect in Ultra-WCCP1(config-subif)#no ip wccp 23

Workaround

Enable service before attach it to an interface. If this problem has happened, a reload will solve this.

Further Problem Description