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Verifying That Unknown Unicast Packets Are Forwarded to a Trunk Interface

Purpose

Verify that a VLAN is forwarding all unknown unicast packets (those with unknown destination MAC addresses) to a single trunk port instead of flooding them out all the ports in the VLAN.

Action

Display the forwarding interface for unknown unicast packets for a VLAN (here, the VLAN name is v1):
user@switch> show configuration ethernet-switching-options
```
unknown-unicast-forwarding {
    vlan v1 {
        interface xe-2:0/0/7.0;
    }
}
```

Display the Ethernet switching table:

user@switch> show ethernet-switching table vlan
v1

Ethernet-switching table: 3 unicast entries
  VLAN              MAC address       Type         Age Interfaces
  v1                *                 Flood          - All-members
  v1                00:01:09:00:00:00 Learn         24 xe-2:0/0/7.0
  v1                00:11:09:00:01:00 Learn         37 xe-2:0/0/3.0

Meaning

The sample output from the show configuration ethernet-switching-options command shows that the unknown unicast forwarding interface for VLAN v1 is interface xe-2:0/0/7. The output of the show ethernet-switching table command shows that an unknown unicast packet is received on interface xe-0/0/3 with the source MAC address (SMAC) of 00:11:09:00:01:00. This shows that the SMAC of the packet is learned in the normal way (through the interface xe-0/0/3.0). The destination MAC address (DMAC) 00:01:09:00:00:00 is learned on interface xe-0/0/7.