Description

This article describes the issue of the configuration of a logical interface to accept untagged packets with interface-mode access not being valid for Trio MPCs or MICs.

Symptoms

Unable to pass traffic on a VLAN access interface with the Trio chipset. Similar messages, such as the following message, are noticed:

root@mx80a# Jan 7 07:27:52 mx80a tfeb0 l2pd_modify_inbound_vlan_tags: vtag is NULL before modify packet

Solution

The configuration of a logical interface to accept untagged packets with the interface-mode access is not valid for Trio MPCs or MICs.

Which product platforms use the Junos Trio chipset?

  • MX 3D MPC line cards

  • 16 port 10-Gigabit Ethernet MPC

  • MX80 (standalone chassis)

Changing the configuration of the access interface will get the access port to work. The current configuration is as follows:

Interface :

ge-1/1/0 {
    unit 0 {
        family bridge {
            interface-mode access;
            vlan-id 999;
Bridge-domain :
vlan-999 {
    domain-type bridge;
    vlan-id 999;
    routing-interface irb.999;
You will have to change the configuration as follows:

Interface :
ge-1/1/0 {
    encapsulation ethernet-bridge
    unit 0 {
        family bridge
Bridge-domain :
vlan-999 {
    domain-type bridge;
    vlan-id 999;
    interface ge-1/1/0.0
    routing-interface irb.999;