Juniper QFX5100 VLAN flood input filter doesn't work

Stanislaw me at nek0.net
Tue Nov 7 22:06:50 CST 2017


Hello, list (again),

I've been trying to use VLAN BUM traffic filter on QFX5100. The 
configuration on the test VLAN was quite trivial:

Model: qfx5100-48s-6q
Junos: 17.2R2.8

# show vlans Testvlan
vlan-id 4030;
forwarding-options {
     filter {
         input Testvlan-ingress;
     }
     flood {
         input Testvlan-flood;
     }
}

I connected two linux hosts to the test VLAN:
# show interfaces ge-0/0/42
unit 0 {
     family ethernet-switching {
         vlan {
             members Testvlan;
         }
     }
}

# show interfaces ge-0/0/43
unit 0 {
     family ethernet-switching {
         vlan {
             members Testvlan;
         }
     }
}

The firewall filter wwas quite simple:
# show firewall family ethernet-switching filter Testvlan-ingress
term accept {
     then accept;
}


The flood input filter I was trying to use.
According to the documentation, only Broadcast, Unknown unicast and 
Multicast (BUM) traffic goes here. The regular unicast traffic should be 
left intact by it.
# show firewall family ethernet-switching filter Testvlan-flood
term allow_arp {
     from {
         ether-type arp;
     }
     then accept;
}
term allow_ipv6_ns {
     from {
         destination-mac-address {
             33:33:ff:00:00:00/24;
         }
         ether-type 0x86dd;
     }
     then accept;
}

term discard_all {
     then discard;
}

I started hosts to ping (and snif) each other.. And I saw only ARP 
requests/responses.

"show ethernet-switching table" displayed that both hosts MAC were 
successfully learned, thus traffic between them should be considered as 
regular unicast.

However, the last term in Testvlan-flood filter was blocking it.
If I replace it with "accept" - traffic begins to flow.

Are any Juniper QFX gurus here? I would really appreciate some advice.


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