IP-TCP_NSR-5-DISABLED log

[Rojer-bkk]

Hi Expert,

Anyone have seen log IP-TCP_NSR-5-DISABLED?  NSR disabled for TCP connection because Retransmission threshold exceeded.
BGP connection cannot be established for while before rollback to be normal. No link flap. Should it be bug software? Thanks

[Alexei Kiritchenko]

Hello Rojer-bkk,

The standby RP is responsible for transmitting TCP information when NSR is used.

The NSR_DISABLED message is seen when the local end TCP goes into repeated retransmission due to not receiving any response from the remote end.   In such a case NSR is

disabled for the affected session(s) so that the active RP again is responsible for sending the BGP messages (just to be sure that it is not the standby RP problem).

IP-TCP_NSR-5-DISABLED itself is not the reason, but a consequence of end to end TCP communication issues.

Regards,

/A

[dougkenline]

What does RP stand for?

[Peter L]

RP = Route Processor

RSP = Route Switch Processor

Depending on what chassi you are using you will have at least one of these cards in your ASR9K.

[netops044]

Hi Alexei,

Could you please explain more clarity for this issue

[Ivan Krimmel]

Hi Rojer,

more precisely one could say after having analyzed all the events which lead this log to come up. Though it is an expected log as Alex explained, there's for instance a software defect filed against it - CSCtq27688. If it was a one-time occurence, then just ignore it and run the box, if that has a pattern or your syslog is saturated by these messages, then let's go for a TAC SR.

I hope this sounds clear.

All the best in the New Year!

Cheers,

Ivan.