Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 1912)

LLDP, LLDP-MED and Voice VLAN Introduction and Configuration
Software Reference for x310 Series Switches
70.8 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Transmission and Reception
Table 70-3 describes the LLDP transmission and reception processes. Additional LLDP-
MED processes are described in “LLDP-MED Operation” on page 70.9 .
Table 70-3: LLDP transmission and reception processes
When ... And ... Then ...
LLDP is enabled Ports are configured to transmit
LLDP advertisements Regular LLDP advertisements are sent via these
ports at intervals determined by the transmit
interval. Each advertisement contains local
information (from the Local Systems MIB) for all the
mandatory TLVs and the optional TLVs that the port
is configured to send.
Ports are configured to receive
LLDP advertisements Information received in advertisements via these
ports is stored in the Neighbor table (Remote
Systems MIB). This information is retained until it is
replaced by a more recent advertisement from the
same neighbor or it times out (the TTL elapses).
Local information
changes The transmission delay time has
elapsed since the last
advertisement was transmitted New advertisements are sent containing the new
set of local information.
Neighbor
information changes Notifications are enabled, and
the notification interval has
elapsed since the last notification
was sent The SNMP notification (trap) lldpRemTablesChange
is sent.
LLDP transmission
and reception is
disabled on a port. An LLDP command was used to
do this It transmits a final ‘shutdown’ LLDPDU with a Time-
To-Live (TTL) TLV that has a value of “0”. This tells
any remote neighboring devices to remove the
information associated with this switch from their
remote systems MIB. Then it stops transmitting and
receiving advertisements. The neighbor
information remains in the Remote Systems MIB
until it times out.
A shutdown command was used
on the port It makes a best effort to send a shutdown LLDPDU.
Then it stops transmitting and receiving
advertisements. The neighbor information remains
in the Remote Systems MIB until it times out.
Something else disabled LLDP,
such as Virtual Chassis Stacking
(VCStack) failover It does not send a shutdown LLDPDU. It stops
transmitting and receiving advertisements. The
neighbor information remains in the Remote
Systems MIB until it times out.
It is enabled again LLDP reinitializes and resumes transmitting and
receiving advertisements after the reinitialization
interval has elapsed.
The Neighbor table
has 1600 neighbors It discards any further neighbors.
LLDP receives a
LLDPDU or TLV with
a detectable error It discards the incorrect TLV.
LLDP receives a TLV it
does not recognize It contains no basic format errors It stores it for possible later retrieval by network
management (in the unrecognized TLV information
table lldpRemUnknownTLVTable in the LLDP MIB).