nat64 icmp need-frag enable

Function

The nat64 icmp need-frag enable command enables the function of NAT64 device to send ICMP NEED FRAG packets to the IPv4 host.

The undo nat64 icmp need-frag enable command disables the function of NAT64 device to send ICMP NEED FRAG packets to the IPv4 host.

Format

nat64 icmp need-frag enable

undo nat64 icmp need-frag enable

Parameters

None

Views

System view

Default Level

2: Configuration level

Usage Guidelines

This function enables the NAT64 device to send ICMP NEED FRAG packets to notify the IPv4 host of the need for packet fragmentation. The Type field of the ICMP NEED FRAG packet is 3 (destination unreachable), and the Code field is 4 (fragmentation needed and DF set). With this function enabled, when translating an IPv4 packet into an IPv6 packet, the NAT64 device sends an ICMP NEED FRAG packet to the IPv4 host if the DF field in the IPv4 packet is set and the size of the resulting IPv6 packet exceeds the path MTU (or the IPv6 MTU configured in nat64 v6out mtu if the path MTU is not specified. The default value is 1280). You can run the undo nat64 icmp need-frag enable command to disable this function.

By default, the NAT64 device is disabled to send ICMP NEED FRAG packets to the IPv4 host.

Example

# Enable the function of NAT64 device to send ICMP NEED FRAG packets to the IPv4 host.

<sysname> system-view
[sysname] nat64 icmp need-frag enable