Cisco ISSU

6500 Jul 26, 2010

During the building and configuration of a number of brand spanking new Cisco 6509’s with Sup720-3C I decided to convert them to VSS mode before updating the IOS (mainly due to laziness and only having console access). The conversion worked a treat however when I can to upgrade the IOS with ISSU I seemed to hit a glitch, the standby sup got itself in a reboot loop.

The error messages seen;

*Jul 26 14:38:21.291: %PFREDUN-SW1_SP-4-PHYSMEM_MISMATCH: Asymmetrical redundant configuration: Active SP has (1048576/8192K) memory, Standby has (1048576/65536K).
*Jul 26 14:38:21.291: %PFREDUN-SW1_SP-4-PHYSMEM_MISMATCH: Asymmetrical redundant configuration: Active RP has (1048576/8192K) memory, Standby has (1048576/65536K).
*Jul 26 14:38:22.307: %PFREDUN-SW1_SP-6-ACTIVE: Standby initializing for RPR mode
*Jul 26 14:38:23.856: %ISSU-SW1_SP-3-FSM_MISMATCH_MTU: ISSU nego failed for client ISSU ifs client(110) entity_id 113 session 393699 due to mismatch of mtu size 72 & 36. : ios-base : (PID=12311, TID=17) : -Traceback=(s72033-advipservicesk9_wan-5-dso-bnp.so+0x94088) ([27:-3]4-dso-b+0x1ED79C) ([37:0]+0x1ED81C) ([27:-3]5-dso-bnp+0x908A4) ([39:0]+0x90B70) ([39:0]+0x91090) ([27:-3]6-dso-b+0x136110) ([27:-9]3+0x39F400) ([37:0]+0x36BF88) ([27:-9]7+0x1AA8A0) ([37:0]+0x1AA878)
*Jul 26 14:38:23.892: %ISSU-SW1_SP-4-FSM_INCOMP: Version of local ISSU client ISSU ifs client(110) in session 393699 is incompatible with remote side.
*Jul 26 14:38:23.892: %RFS-SW1_SP-3-START_NEGO_SESSION: RFS nego (393699:590199) to [issu:rfs:Secondary RFS Server Port:0x4050000] failed: [ISSU_RC_NEGO_ERROR]

After trying a couple of things (and not having patience) I decided to break out into ROMMON and reload with config-register of 0x2142 so that I could stop the roboot loop and put VSS into standalone mode. Although this worked a treat and I had both 6500 in standalone mode and with blank configuration (wr erase) I was unable to do anything on upgradeing the image as ISSU seemed to get stuck in it upgrade process;

Router#sh issu state detail
                          Slot = 5
                      RP State = Active
                    ISSU State = System Reset
                 Boot Variable = bootdisk:s72033-advipservicesk9_wan-vz.122-33.S
XI2a.bin,12;
                Operating Mode = sso
               Primary Version = bootdisk:s72033-advipservicesk9_wan-vz.122-33.S
XI2a.bin
             Secondary Version = bootdisk:s72033-advipservicesk9_wan-vz.122-33.S
XI2a.bin
               Current Version = bootdisk:s72033-advipservicesk9_wan-vz.122-33.S
XI2a.bin
                Variable Store = PrstVbl
% Standby information is not available because it is in 'DISABLED' state

Router(config)#boot system flash sup-bootdisk:s72033-advipservicesk9_wan-vz.122-33.SXI2a.bin
% ISSU process is in progress; Boot variable can not be updated.

Router#issu abortversion
The system is without a fully initialized peer and Service impact will occur. Pr
oceed with abort? [confirm]
% ISSU process can be aborted only from [ Load Version ] or [ Run Version ] or [
 Load Version - Switchover ] or [ Run Version - Switchover ] state

After trying a couple of command and looking on google I was no closer to getting the box back in a state that I could do anything with….until it dawned on me “I wonder if a clear command exists for ISSU to reset the flag”. Well yes it does;

Router#clear issu state
 
Router#sh issu state detail
                          Slot = 5
                      RP State = Active
                    ISSU State = Init
                 Boot Variable = bootdisk:s72033-advipservicesk9_wan-vz.122-33.S
XI2a.bin,12;
                Operating Mode = sso
               Primary Version = N/A
             Secondary Version = N/A
               Current Version = bootdisk:s72033-advipservicesk9_wan-vz.122-33.S
XI2a.bin
                Variable Store = PrstVbl
% Standby information is not available because it is in 'DISABLED' state

Once I put the config-register back and added the required boot statement I was at a point in which I can re-convert the VSS.

Tags

Rob Edwards

Northern (UK) chap focusing on platforms, automation, cloud and cloud native applications. Recovering network engineer, although it turns out networking is as important, if not more, now than before!

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