The number of controller and interface ups and downs in this log sound more like a line issue than a config issue. Without knowing how it is configured it is difficult to know whether there is some configuration issue that is contributing to this. If you could post some configuration details and also post the output of show controller t1 it might give us more to work with.
Thank you for posting the config. I believe that it is helpful. It gets into an area where I do not have much experience, channelizing the T1 so that a couple of channels carry data traffic (including your BGP) and the rest of the channels for voice traffic.
I believe that it is also helpful that you posted the output of show controller T1. It does not show errors in the last 2 hours and 36 minutes. Would I be correct in assuming that the router might have been reboot 2 hours and 36 minutes before this output was generated? From the lack of errors shown on the T1 controller I am wondering if the voice equipment that is sharing the T1 might be doing something that impacts the data channels.
By this I'm certain that for the last 24 hours there are no issues with the CSU/DSU.
Secondly, I shall be humble over this to admit that I have never worked before on CAS mode T1 configuration.
Secondly, I have had once instance of a T1 link failure when the Carrier unknowingly put Loop on their side and the controller and the link went crazy. However since we had an external CSU/DSU we saw the Loop LED glow.
Over here in the message also says that it has detected a Loop, so could you please check with the Carrier if they have had no hand in this entire episode.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...