Exceptions To The Vlan Forwarding Rules; Special Considerations; Special Use Of Vlan Id=0; Automatic Failback Of Vlan Tagging - Avaya J100 Series Installing And Administering

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Virtual LAN (VLAN)

Exceptions to the VLAN forwarding rules

Exceptions to the VLAN forwarding rules are as follows:
• LLDP frames are always exchanged between the following in all VLAN separation modes:
- The LAN port and CPU port
- The CPU port and LAN port
• Spanning tree frames are always exchanged between the LAN port and PC port in all VLAN
separation modes.
• 802.1x frames are always exchanged between the following in all VLAN separation modes
according to DOT1XSTAT and DOT1X configuration:
- The LAN and CPU port or PC port
- The PC and CPU port or LAN port
- The CPU port and LAN port
Related links
Virtual LAN (VLAN)

Special considerations

Special use of VLAN ID=0

The phone adds a VLAN tag to the egress voice frames with a VLAN ID=0 in certain
configurations. For example, to utilize the priority functionality of the VLAN frame only and not the
VLAN ID properties. In this case, use the parameter L2QAUD or L2QSIG to set the value of the
VLAN priority portion of the VLAN tag.

Automatic failback of VLAN tagging

The phone connects to a network when the value of L2QVLAN does not match with the VLAN
being assigned to the network access switch. When the phone starts to connect, it tries to contact
the DHCP server with a VLAN ID=L2QVLAN. If the phone does not receive a DHCPOFFER with
that particular VLAN ID, then it eventually fails back. The phone tries to contact the DHCP server
again if the VLAN functionality of the phone is set to one of the following:
• L2Q=1: With a VLANID =0
• L2Q=0: Without any VLAN tag
The VLANTEST parameter determines how long the phone waits for a recognizable
DHCPOFFER. If VLANTEST= 0, then the phone does not fail back and keeps sending DHCP
requests by using tagged VLAN frames with VLAN ID = L2QVLAN.
July 2019
on page 54
on page 54
Installing and Administering Avaya J100 Series IP Phones
Comments on this document? infodev@avaya.com
Virtual LAN (VLAN)
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