Dell BigIron RX Series, Configuration Manual

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BigIron RX Series Configuration Guide 265
53-1002253-01
Configuring LLDP
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where <seconds> is a value between 1 and 8192. The default is two seconds. Note that this value
must not be greater than one quarter of the LLDP transmission interval (CLI command lldp
transmit-interval).
Changing the interval between regular LLDP transmissions
The LLDP transmit interval specifies the number of seconds between regular LLDP packet
transmissions. When you enable LLDP, by default, the device will wait 30 seconds between regular
LLDP packet transmissions. If desired, you can change the default behavior from 30 seconds to a
value between 5 and 32768 seconds.
To change the LLDP transmission interval, enter a command such as the following at the Global
CONFIG level of the CLI.
BigIron RX(config)#lldp transmit-interval 40
The above command causes the LLDP agent to transmit LLDP frames every 40 seconds.
Syntax: [no] lldp transmit-interval <seconds>
where <seconds> is a value from 5 to 32768. The default is 30 seconds.
NOTE
Setting the transmit interval or transmit holdtime multiplier to inappropriate values can cause the
LLDP agent to transmit LLDPDUs with TTL values that are excessively high. This in turn can affect
how long a receiving device will retain the information if it is not refreshed.
Changing the holdtime multiplier for transmit TTL
The holdtime multiplier for transmit TTL is used to compute the actual time-to-live (TTL) value used
in an LLDP frame. The TTL value is the length of time the receiving device should maintain the
information in its MIB. When you enable LLDP, the device automatically sets the holdtime
multiplier for TTL to four. If desired, you can change the default behavior from four to a value
between two and ten.
To compute the TTL value, the system multiplies the LLDP transmit interval by the holdtime
multiplier. For example, if the LLDP transmit interval is 30 and the holdtime multiplier for TTL is 4,
then the value 120 is encoded in the TTL field in the LLDP header.
To change the holdtime multiplier, enter a command such as the following at the Global CONFIG
level of the CLI.
BigIron RX(config)#lldp transmit-hold 6
Syntax: [no] lldp transmit-hold <value>.
where <value> is a number from 2 to 10. The default value is 4.
NOTE
Setting the transmit interval or transmit holdtime multiplier to inappropriate values can cause the
LLDP agent to transmit LLDPDUs with TTL values that are excessively high. This in turn can affect
how long a receiving device will retain the information if it is not refreshed.