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What does Fabricpath Ftag 0 do?

I have two nx5500 switches with sid 10 (sw1) and 20 (sw2). they are connected by a single link (eth1/31). I have a vlan configured in fabricpath mode with an access port on each of the switches.

I am trying to understand how fabricpath routing works here. when I run "show fabricpath route" I get the following output:

 

on SW1:

0/10/0, number of next-hops: 0
        via ---- , [60/0], 1 day/s 22:23:40, local
1/20/0, number of next-hops: 1
        via Eth1/31, [115/40], 0 day/s 21:07:08, isis_fabricpath-default

 

on SW2:

0/20/0, number of next-hops: 0
        via ---- , [60/0], 2 day/s 01:35:43, local
1/10/0, number of next-hops: 1
        via Eth1/31, [115/40], 0 day/s 21:07:05, isis_fabricpath-default

When I wireshark on the connection between the two switches, I see packets with ftag 1 going from SW1 to SW2, which is expected. What I don't understand is how those packets are getting delivered at SW2. There is no entry in the RIB of SW2 matching on ftag 1 with 'local' as output port. However there is an entry with Ftag 0.

How do these 'local' route entries (which have ftag0) match on packets that have a different ftag?

 

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