Have you noticed a slow down in internet response?
Usually the lan connection should remain steady on, if intermittent
blinking, you are losing the sync signal, could be anything, noise on
the line, moisture in the connections, etc, call Comcast or whoever
is your ISP.
Sort of expanding on that:
Depends on what "Lan1" means. If it's the DSL connection, it should be
on steady. Blinking means it's looking to sync up to the signal and not
working.
If it means a connected computer, that will blink when data passes.
Comms between the PC and router will keep those blinking at various
times, not usualy steady on or off. On my router, if it's on steady =
no data movement, blinking means data movement.
HTH