Symptom
Link may go to errdisable state with "UDLD empty echo" very rarely when line card reload
Conditions
On 10G board, configure
1. UDLD protocol enabled
2. Option "system default link-fail laser-on" enabled
3. interface debounce time is set to 0
then reload the line card.
Workaround
1. shut/no shut the port that in "errdisable" state, or
2. configure the link debounce time to 10ms or larger, or
3. disable the UDLD protocol, or
4. configure "no system default link-down laser-on" option
Further Problem Description
