[j-nsp] Interface link State Tracking

[Ivan]

I have quite a lot of experience with Cisco switches and am starting to
also implement Juniper switches.  Cisco switches have a feature "link
state tracking"
(http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_25_see/configuration/guide/swethchl.html#wp1285238)
which I so far have been unable to find on the Junipers (EX4200).  It
would be helpful if someone could point me to the equivalent Juniper
feature or confirm that it is not available.

Thanks

Ivan