Lantronix
SM12XPA Web User Guide
33848 Rev. A
Page
29
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473
Tx Delay
: If some configuration is changed (e.g., the IP address) a new LLDP frame is transmitted, but the time
between the LLDP frames will always be at least the value of Tx Delay seconds. Tx Delay cannot be larger than
1/4 of the Tx Interval value. Valid values are restricted to 1 - 8192 seconds.
Tx Reinit
: When a port is disabled, LLDP is disabled or the switch is rebooted, an LLDP shutdown frame is
transmitted to the neighboring units, signaling that the LLDP information isn't valid anymore. Tx Reinit controls
the time between the shutdown frame and a new LLDP initialization. Valid values are 1 - 10 seconds.
LLDP Port Configuration
:
Port
: The switch port number of the logical LLDP port.
Mode
: Select an LLDP mode:
Rx
only
: The switch will not send out LLDP information, but LLDP information from neighbor units is
analyzed.
Tx
only
: The switch will drop LLDP information received from neighbors but will send out LLDP
information.
Disabled
: The switch will not send out LLDP information and will drop LLDP information received from
neighbors.
Enabled
: the switch will send out LLDP information and will analyze LLDP information received from
neighbors.
CDP Aware
: Select Cisco Discovery Protocol awareness.
CDP operation is restricted to decode incoming CDP frames (the switch doesn't transmit CDP frames).
CDP frames are only decoded if LLDP on the port is enabled.
Only CDP TLVs that can be mapped to a corresponding field in the LLDP neighbors’ table are decoded. All other
TLVs are discarded (Unrecognized CDP TLVs and discarded CDP frames are not shown in the LLDP statistics.).
CDP TLVs are mapped onto LLDP neighbors’ table as shown below.
CDP TLV "Device ID" is mapped to the LLDP "Chassis ID" field.
CDP TLV "Address" is mapped to the LLDP "Management Address" field. The CDP address TLV can contain
multiple addresses, but only the first address is shown in the LLDP neighbors’ table.
CDP TLV "Port ID" is mapped to the LLDP "Port ID" field.
CDP TLV "Version and Platform" is mapped to the LLDP "System Description" field.
Both the CDP and LLDP support "system capabilities", but the CDP capabilities cover capabilities that are not
part of the LLDP. These capabilities are shown as "others" in the LLDP neighbors’ table.
If all ports have CDP awareness disabled, the switch forwards CDP frames received from neighbor devices.
If at least one port has CDP awareness enabled, all CDP frames are terminated by the switch.
Note
: When CDP awareness on a port is disabled, the CDP information isn't removed immediately but gets
removed when the hold time is exceeded.
Trap
: LLDP trapping notifies events such as newly-detected neighbor devices and link malfunctions.
Port Descr
: Optional TLV: When checked the "port description" is included in LLDP information transmitted.
Sys Name
: Optional TLV: When checked the "system name" is included in LLDP information transmitted.
Sys Descr
: Optional TLV: When checked the "system description" is included in LLDP information transmitted.
Sys Capa
: Optional TLV: When checked the "system capability" is included in LLDP information transmitted.