Manual

Layer 2 Tunnel Protocol Version 3
ip dfbit set
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Cisco IOS Releases 12.0(29)S and 12.2(25)S
ip dfbit set
To enable the Don’t Fragment (DF) bit in the outer Layer 2 Tunnel Protocol Version 3 (L2TPv3) header,
use the ip dfbit set command in pseudowire class configuration mode. To disable the DF bit setting, use
the no form of this command.
ip dfbit set
no ip dfbit set
Syntax Description This command has no arguments or keywords.
Defaults The default value is DF bit off, except for Cisco 12000 series Internet routers, which have this command
enabled by default.
Command Modes Pseudowire class configuration
Command History
Usage Guidelines Use this command to set the DF bit on if, for performance reasons, you do not want tunneled packet
reassembly to be performed on the router.
Note On Cisco 12000 series Internet routers, the no ip dfbit set command is supported only in Cisco IOS
Release 12.0(24)S and later releases.
Examples The following example shows how to enable the DF bit in the outer L2TPv3 header in pseudowires
created from the pseudowire class named ether-pw:
Router(config)# pseudowire-class ether-pw
Router(config-pw)# ip dfbit set
Related Commands
Release Modification
12.0(23)S This command was introduced.
12.2(25)S This command was integrated into Cisco IOS Release 12.2(25)S.
Command Description
ip pmtu Enables the discovery of a PMTU for L2TPv3 traffic.
pseudowire-class Specifies the name of an L2TP pseudowire class and enters pseudowire
class configuration mode.