VLAN Detection

The Avaya IP Telephones support automatic detection of the condition where the L2QVLAN setting is incorrect. When VLAN tagging is enabled (L2Q= 0 or 1) initially the 4600 Series IP Telephone transmits DHCP messages with IEEE 802.1Q tagging and the VLAN set to L2QVLAN. The telephones will continue to do this for VLANTEST seconds.

• If the VLANTEST timer expires and L2Q=1, the telephone sets L2QVLAN=0 and transmits DHCP messages with the default VLAN (0).
• If the VLANTEST timer expires and L2Q=0, the telephone sets L2QVLAN=0 and transmits DHCP messages without tagging.
• If VLANTEST is 0, the timer will never expire.

NOTE: Regardless of the setting of L2Q, VLANTEST, or L2QVLAN, you must have DHCP administered so that the telephone will get a response to a DHCPDISCOVER when it makes that request on the default (0) VLAN.

After VLANTEST expires, if an Avaya IP Telephone running R2.6 receives a non-zero L2QVLAN value, the telephone will release the IP Address and send DHCPDISCOVER on that VLAN. Any other release will require a manual reset before the telephone will attempt to use a VLAN on which VLANTEST has expired. See the Reset procedure in Chapter 3 of the 4600 Series IP Telephone Installation Guide.

The telephone ignores any VLAN ID administered on the media server if a non-zero VLAN ID is administered either:

• by LLDP
• manually,
• through DHCP, and/or
• through TFTP or HTTP.