Router Logs

Unanswered Question
Sep 11th, 2009


We have monitored some logs on our cisco 1700 series router.



On executing "sh int Serial" command we are getting output, where last line is.

DCD=up DSR=up DTR=up RTS=up CTS=down

I guess CTS=down means there may be some problem with router software/IoS. Is this right...? If not then please share the cause for this, also share how to fix the problem.




On executing "sh logg" command on router, it also gives below logs.

*Sep 7 12:10:09 UST: %SNMP-5-COLDSTART: SNMP agent on host DIMAT is undergoing

a cold start

Requesting to please share the reason of such logs.

I have this problem too.
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Richard Burts Fri, 09/11/2009 - 08:44


I believe that both of these messages are normal operational things and not anything to be concerned about.

The indicators on the serial interface show a low level indication of the state of the serial connection:

DCD is Carrier Detect and is up

DSR is Data Set Ready and is up

DTR is Data Terminal Ready and is up

RTS is Ready to Send and is up

CTR is Clear to Send and is down I do not believe that this is a real error condition.

The other message is a message that is generated at boot time. The IOS has an SNMP agent which is what allows IOS to respond to the SNMP server and to generate SNMP traps. At boot time the SNMP agent goes through a cold start. This is quite normal.



Giuseppe Larosa Sun, 09/13/2009 - 14:35

Hello Jimmy,


CTS is a signal sent from DCE to the router (that is the DTE) it should be up to allow the DTE router to send data.

if this has been a temporary condition this shouldn't be a great problem.


as Rick has explained it is a normal message during router bootup process and it is nothing to worry about.

Hope to help



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