EX can only count packet sent to the kernel ( BCM limitation )
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jlk@ex4600-1> show configuration interfaces ge-0/0/1.456 | display set
set interfaces ge-0/0/1 unit 456 vlan-id 456
set interfaces ge-0/0/1 unit 456 family ethernet-switching filter input inputethfilter
set interfaces ge-0/0/1 unit 456 family ethernet-switching filter output outputethfilter
jlk@ex4600-1> show firewall filter outputethfilter
jlk@ex4600-1> show firewall filter inputethfilter
filter for IP:
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set interfaces ge-0/0/1 unit 456 family inet filter input dasad