- You should setup a central syslog-server , and redirect logging to it for all involved devices, and check for troublesome messages when this is done, and also when not effectively . Note that if you have sub interfaces configured on a router then check the ip addresses. You cannot have the same ip addresses configured on the switch svis as you do on the router sub-interfaces.
-- ' A nun once asked a penguin 'do you think the earth is flat ? ; the penguin replied :
Madam, it all depends in Riemann geometries the earth can be perfectly flat! The nun thanked him , he tripped and fell forward : the poor animal had forgotten that he might be living in a Riemann geometry too!