I am a cisco academy student and I am attending courses within the Dallas Fort Worth area. I wish to know how I can identify why the interfaces in our lab are flapping. I have discussed this with my professor and he mentioned that this is a known issue with the newer interfaces that they purchased and that sometimes there is irregular flapping on wic-2t interfaces within the lab. I am sure that he is taking steps to isolate and troubelshoot the problem but I was wondering what are the most useful debug commands, best practices I could use to see why an interface is flapping. So long as an interface is configured properly with the right IP address, mask, clocking if needed, then it should not flap, but if it does other than swapping out wic cards and replacing cables (which I already did with my professor) if the interface continues to flap how can I troubleshoot?
Sometimes with these troubled interfaces the line protocol will never come up. In that case is there any reccomended way to troubleshoot these issues.
Thank you in advance!