Lost the Internet Connection to ISP for few mins on Cisco ASR

[mahesh18]

We have Cisco ASR running BGP with ISP and we are learning full routing table.

Today users reported Internet Connection dropping.

Check the ASR routers all look good like

Routes learned are few weeks old.

No errors on the physical interfaces.

BGP nei established since a year.

Spoke to ISP they do not see any issue on their side.

IS there any way or CLI command to check  the health of ASR?

or to find if ASR dropped any traffic during that time period?

[networkcheff]

To check what happened you can always have a look on the log messaged during the time of issue. 

Use show diag 

[mahesh18]

Seems we are not logging the messages to external syslog.

they are overwritten on the router.

show diag ?
all All related information
chassis Chassis related information
slot Slot location information for this command
subslot Subslot location information for this command

which option should i use?

[Richard Burts]

Of the options available I do not see where slot or subslot would have any information helpful about your routing issue. And I am not optimistic that chassis would have much helpful but it certainly does not hurt to give it a try (and in fact not being sure about it I would say it would not hurt to try the all option). If the only logging enabled is logging buffer (or perhaps buffer and monitor) then the log files do get overwritten. You might try the show log command and see if perhaps there might be helpful entries that have not yet been written over.

HTH

Rick

[mahesh18]

Nice to see Reply from you Rich.

Try all the options no info linked to Routing issue.

As our logging buffer is very small logs are overwritten.

Try to escalate with ISP to dig deeper and check all the upstream devices

Best Regards

Mahesh

[Richard Burts · Accepted solution]

Mahesh

Sorry that show diag did not have helpful information, but not surprised. It may be grasping at straws but is it possible that there was some issue on your ASR (rather than the with the ISP) and that devices downstream from the ASR might have logged something?

HTH

Rick

[mahesh18]

Seems did deep dive in our internal network and found that Core MPLS router interface went down and that caused all the 

internal OSPF routes to refreshed and re converged.

IT is good ot know what happened

[Richard Burts]

Mahesh

Thanks for the update. It is indeed good to know what happened. I am glad that my suggestion pointed you in the right direction. Thank you for marking this question as solved.

HTH

Rick