I'm trying to understand the reasons for seeing LINEPROTO-5-UPDOWN which I believe is a change in the data link layer? As seems to be the case for others, the down and up action only take a few seconds and occur at random instances.
I'm seeing these messages in our syslog trap across various switches in the network. I'm not too concerned about it happening on desktops but it's also happening on the 3560 we are using as a 'WAN link aggregator'.
We have various branch offices connected over 2MB SDH links, where the CPE equipment is a Pandatel E1 - Ethernet converter at each end (Branch-HQ).
At the HQ all these branches have their ethernet ports from the pandatel terminated on a 3560.
Two of these ports are causing LINEPROTO-5-UPDOWN issues at random. Is this Link Flapping?
I would like to better understand this to see whether this could be coming from the SDH side or not.