xbprc link flapping between NPM and APM

Products

• XOS

Issue/Introduction

xbprc messages are logged to report the backplane link connectivity status between an NPM and an APM. If the link is flapping consistently then there is a possibility of a hardware fault with the NPM, APM or the X-Series chassis1. Traffic outages are experienced for traffic passing through a specific vap member.

2. The xbprc messages in the logs show the port going up and down consistently.
Here is an example, where the port is seen flapping consistently for the connectivity between the NPM in slot 3 and the APM in slot 7:
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Nov 1 02:16:55 npm3 kernel: xbprc: sdp-5: link to slot-7 is down due to tlk-5 event.
Nov 1 02:16:55 npm3 kernel: xbprc: sdp-5 (slot-7): Port is down
Nov 1 02:16:55 npm3 kernel: xbprc: sdp-5 (slot-7): flow=>fail
Nov 1 02:16:56 npm3 kernel: xbprc: sdp-5: Reconfigured speed to 6 Gbs
Nov 1 02:16:56 npm3 kernel: xbprc: sdp-5 (slot-7): fail=>down
Nov 1 02:16:57 POD02 cbshmonitord[4729]: [I] [POD02 1.1.2.20] chassis fault counters: 2 1 1
Nov 1 02:16:57 POD02 cbsflowcalcd[4777]: [I] [POD02 1.1.2.20] Updating NP3 (1.1.2.3) in database
Nov 1 02:16:57 vsx_1 cbsvapcfgd[4647]: [W] [VSX_1 1.1.2.101] No SDP path to NPM3
Nov 1 02:16:57 npm3 kernel: xbprc: sdp-5 (slot-7): down=>wait
Nov 1 02:16:58 npm3 kernel: xbprc: sdp-5 (slot-7): wait=>init
Nov 1 02:16:59 npm3 kernel: xbprc: sdp-5 (slot-7): init=>sync
Nov 1 02:17:00 npm3 kernel: xbprc: sdp-5 (slot-7): sync=>flow
Nov 1 02:17:00 npm3 kernel: xbprc: sdp-5 (slot-7): Port is up
Nov 1 02:17:01 POD02 cbsflowcalcd[4777]: [I] [POD02 1.1.2.20] Updating NP3 (1.1.2.3) in database
Nov 1 02:17:01 npm3 kernel: xbprc: sdp-5: link to slot-7 is down due to tlk-5 event.
Nov 1 02:17:02 npm3 kernel: xbprc: sdp-5 (slot-7): Port is down
Nov 1 02:17:02 npm3 kernel: xbprc: sdp-5 (slot-7): flow=>fail
Nov 1 02:17:02 npm3 kernel: xbprc: sdp-5: Reconfigured speed to 6 Gbs
Nov 1 02:17:02 npm3 kernel: xbprc: sdp-5 (slot-7): fail=>down
Nov 1 02:17:04 npm3 kernel: xbprc: sdp-5 (slot-7): down=>wait
Nov 1 02:17:04 npm3 kernel: xbprc: sdp-5 (slot-7): wait=>init
Nov 1 02:17:05 npm3 kernel: xbprc: sdp-5 (slot-7): init=>sync
Nov 1 02:17:05 POD02 cbsflowcalcd[4777]: [I] [POD02 1.1.2.20] Updating NP3 (1.1.2.3) in database
Nov 1 02:17:05 vsx_1 cbsvapcfgd[4647]: [W] [VSX_1 1.1.2.101] No SDP path to NPM3
Nov 1 02:17:06 npm3 kernel: xbprc: sdp-5 (slot-7): sync=>flow
Nov 1 02:17:06 npm3 kernel: xbprc: sdp-5 (slot-7): Port is up
Nov 1 02:17:07 POD02 cbsflowcalcd[4777]: [I] [POD02 1.1.2.20] Updating NP3 (1.1.2.3) in database
Nov 1 02:17:07 npm3 kernel: xbprc: sdp-5: link to slot-7 is down due to tlk-5 event.
Nov 1 02:17:08 npm3 kernel: xbprc: sdp-5 (slot-7): Port is down

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Cause

xbprc messages are logged to report the backplane link connectivity status between an NPM and an APM, and are generally considered to be normal messages.
However, if the link is flapping consistently within seconds as shown in the example above then it may be due to a hardware fault with the NPM, APM or the X-Series chassis.

Resolution

Perform the following troubleshooting steps need to be performed to identify if there is hardware fault with APM, NPM, or the chassis.

Step 1: Move the APM to a different slot. If the xbprc messages continue occurring for the new APM slot, then it would indicate a hardware fault with the APM.

Step 2: If the messages stop after moving the APM, then insert an APM back to the original slot, verify the xbprc messages are occurring and move the NPM to a different slot. If the xbprc messages follow the NPM and occur for the new NPM slot, then it would indicate a hardware fault with the NPM.

Step 3. If the issue doesn't follow the APM or the NPM, then different APM and NPM modules in the original slots. If the xbprc messages continue to occur for the same slots after the swap of the modules, then it would indicate a hardware fault with the X-Series chassis.

Please contact Blue Coat support to request an RMA, provide the log files along with the timeline of when the above steps were performed.