please refer and check , also change to another port 2/0/1 or other
http://forums.juniper.net/t5/Ethernet-Switching/curious-problem-interface-EX4200-down/td-p/93880
please refer and check , also change to another port 2/0/1 or other
http://forums.juniper.net/t5/Ethernet-Switching/curious-problem-interface-EX4200-down/td-p/93880