Alcatel-Lucent 7450 Configuration Manual page 150

Router L2TP Commands
Description
This command configures the use of challenge-response authentication.
The no form of the command reverts to the default never value.
Parameters always — Specifies that the challenge-response authentication is always used.
df-bit-lac
Syntax df-bit-lac {always|never}
no df-bit-lac
Context config>router>l2tp
config>service>vprn>l2tp
Description By default, the LAC df-bit-lac is always set and sends all L2TP packets with the DF bit set to 1. The
DF bit is configurable to allow downstream routers to fragment the L2TP packets. The LAC itself
will not fragment L2TP packets. L2TP packets that have a larger MTU size than what the LAC
egress ports allows are dropped.
Default df-bit-lac always
Parameters always — Specifies that the LAC will send all L2TP packets with the DF bit set to 1.
never — Specifies that the LAC will send all L2TP packets with the DF bit set to 0.
df-bit-lac
Syntax df-bit-lac {always|never|default}
no df-bit-lac
Context config>router/service>vprn>l2tp>group
config>router/service>vprn>l2tp>group>tunnel
Description By default, the LAC df-bit-lac is set to default and sends all L2TP packets with the DF bit set to 1.
The DF bit is configurable to allow downstream routers to fragment the L2TP packets. The LAC
itself will not fragment L2TP packets. L2TP packets that have a larger MTU size than what the LAC
egress ports allows are dropped. The configuration of the df-bit can be overridden at different levels:
l2tp, tunnel, and group. The configuration at the tunnel level overrides the configuration on both
group and l2tp. The configuration at the group level overrides the configuration on l2tp.
Default df-bit-lac default
Parameters always — Specifies that the LAC will send all L2TP packets with the DF bit set to 1.
never — Specifies that the LAC will send all L2TP packets with the DF bit set to 0.
default — Follows the DF-bit configuration specified on upper levels.
Page 150
Default
no challenge
Values always
7450 ESS Router Configuration Guide