2 weeks ago
Just sharing some info for future reference. After upgrading from Cisco switchs 3560 to 2960X we saw that some ports that were connected to the IAP´s started flapping. After a lot of debug and trial and error configs to no avail i found a reported Cisco bug (https://bst.cloudapps.cisco.com/bugsearch/bug/CSCu
s35889/?referring_site=bugquickviewclick) for this platform (not for my IOS, but cisco never fixed it so it is probably present in all 15.x IOS). The fix is to use the "no power efficient-ethernet" command at the switch ports.