Im not seeing ANY packets on my Wireshark box using the below config. Doesn't make any sense...Should be easy!
WAN-->EX4500-->dedicated pcap trunk-->EX4200-->Wireshark Machine
#EX4500 (Capture Switch)
set interfaces ge-0/0/0 description "WAN Link"
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members Data-MSPP
set interfaces ge-0/0/38 description "PCAP trunk to EX4200-AS ge-0/1/2"
set interfaces ge-0/0/38 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/38 unit 0 family ethernet-switching vlan members WAN-PCAP
set vlans Data-MSPP vlan-id 100
set vlans WAN-PCAP vlan-id 777
set ethernet-switching-options analyzer PCAP loss-priority high
set ethernet-switching-options analyzer PCAP input ingress interface ge-0/0/0.0
set ethernet-switching-options analyzer PCAP input egress interface ge-0/0/0.0
set ethernet-switching-options analyzer PCAP output vlan WAN-PCAP
#EX4200 (Remote Switch)
set interfaces ge-0/1/2 description "PCAP trunk to EX4500 ge-0/0/38"
set interfaces ge-0/1/2 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/1/2 unit 0 family ethernet-switching vlan members WAN-PCAP
set interfaces ge-0/0/0 description "Wireshark"
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members WAN-PCAP
set vlans WAN-PCAP vlan-id 777