In general, it is better to ping beyond
the router as a test that to the router.
But when doing a ping test, if you see
packet loss you may want to have a
look at the following:
- show interface - ensure that there
are no drops or errors
- debug ip icmp - ensure that we are
receiving all the ICMP echo requests
- try disabling WFQ, if enabled
- try disabling fast switching, if
enabled.
(Note these last 2 are workarounds, and
not fixes).