Cisco Cisco Packet Data Interworking Function (PDIF)
APN Configuration Mode Commands
▀ data-tunneling ignore df-bit
▄ Command Line Interface Reference, StarOS Release 18
1332
data-tunneling ignore df-bit
Controls the handling of the DF (Don't Fragment) bit present in the user IPv4/IPv6 packet for tunneling used for the
Mobile IP data path.
Mobile IP data path.
Product
GGSN
P-GW
SAEGW
Privilege
Security Administrator, Administrator
Mode
Exec > Global Configuration > Context Configuration > APN Configuration
configure > context context_name > apn apn_name
Entering the above command sequence results in the following prompt:
[context_name]host_name(config-apn)#
Syntax
[ default | no ] data-tunneling ignore df-bit
default
Restores the data-tunneling parameter to its default setting of disabled.
no
Disables this option. The DF bit in the tunneled IP packet header is not ignored during tunneling. This is the
default setting.
default setting.
ignore df-bit
Ignores the DF bit in the tunneled IP packet header during tunneling. This is the default setting.
Usage
Use this command to configure a user so that during Mobile IP tunneling the DF bit is ignored and packets
are fragmented.
If this feature is enabled, and fragmentation is required for the tunneled user IPv4/IPv6 packet, then the DF
bit is ignored and the packet is fragmented. Also the DF bit is not copied to the outer header.
In the GGSN, this command also affects the other L3 tunneling options, IP-in-IP and GRE, but does not
affect L2TP tunneling.
are fragmented.
If this feature is enabled, and fragmentation is required for the tunneled user IPv4/IPv6 packet, then the DF
bit is ignored and the packet is fragmented. Also the DF bit is not copied to the outer header.
In the GGSN, this command also affects the other L3 tunneling options, IP-in-IP and GRE, but does not
affect L2TP tunneling.
Example
To enable fragmentation of a subscribers packets over a MIP tunnel even when the DF bit is present, enter the
following command:
following command:
data-tunneling ignore df-bit