nat64 alg

Function

The nat64 alg command enables the Network Address Translation IPv6-to-IPv4 (NAT64) application level gateway (ALG) function.

The undo nat64 alg command disables the NAT64 ALG function.

By default, the NAT64 ALG function is enabled for ICMP, regardless of whether the NAT64 ALG function is configured.

This command is supported only on the NetEngine 8000 F1A.

Format

nat64 alg { ftp [ rate-threshold value ] | dns | http | all }

undo nat64 alg { ftp [ rate-threshold [ value ] ] | dns | http | all }

Parameters

Parameter	Description	Value
ftp	Enables or disables the NAT64 ALG function for the FTP protocol.	-
rate-threshold value	Sets the rate limit on FTP packets.	The value is an integer ranging from 64 to 15000, in packets/second.
dns	Enables or disables the NAT64 ALG function for the DNS protocol.	-
http	Enables or disables the NAT64 ALG function for the HTTP protocol.	-
all	Enables or disables the NAT64 ALG function for all application layer protocols.	-

Views

NAT64 instance view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
nat	write

Usage Guidelines

Usage Scenario

The application level gateway (ALG) provides transparent translation for some application layer protocols. For special protocols (for example, FTP) the Data field in a packet contains IP address or port information. NAT64, however, does not take effect on an IP address or port information in the Data field of a packet. As a result, a protocol-specific connection fails to be established. A good way to solve the NAT64 issue for these special protocols is to use the ALG function. Functioning as a special conversion agent for application protocols, the ALG interacts with the NAT64 device to establish states. The ALG uses NAT64 state information to change the specific data in the Data field of IP packets and to complete other necessary work, so that application protocols can run across internal and external networks.

Configuration Impact

After the ALG function is enabled in the NAT64 instance view, traffic of specified application protocols in a specified NAT64 instance can be processed by the ALG.

Example

# Enable the NAT64 ALG function for the FTP protocol and configure the rate limit on FTP packets to be 4000 p/s in the view of a NAT64 instance named nat1.

<HUAWEI> system-view
[~HUAWEI] nat64 instance nat1 id 1
[*HUAWEI-nat64-instance-nat1] nat64 alg ftp rate-threshold 4000