4.14. Network Address Translation (NAT)

This chapter describes commands for configuring Network Address Translation on Mpd's interfaces. NAT is implemented by ng_nat(4) node. To enable it on a particular interface nat option should be used.

Note: ng_nat node is available only on FreeBSD 6.0-RELEASE and newer. Some additional options like setting target address implemented in later versions.

set nat address ip

Set alias IP address. If not specified, interface IP will be used.

set nat target ip

Set target IP address for unknown incoming packets. If not specified, packet will not be modified.

set nat red-addr alias_addr local_addr

Redirect traffic for public (alias) IP address to a machine on the local network.

set nat red-proto proto alias_addr local_addr [ remote_addr ]

Redirect traffic of specified protocol for public (alias) IP address (optionally from specified remote address) to a machine on the local network.

set nat red-port proto alias_addr alias_port local_addr local_port [ remote_addr remote_port ]

Redirect incoming connections arriving to given public (alias) address and port, (optionally from specified remote address) to a host and port of a machine on the local network.

unset nat red-addr alias_addr local_addr

Deletes specific set nat red-addr ... rule.

unset nat red-proto proto alias_addr local_addr [ remote_addr ]

Deletes specific set nat red-proto ... rule.

unset nat red-port proto alias_addr alias_port local_addr local_port [ remote_addr remote_port ]

Deletes specific set nat red-port ... rule.

set nat enable option ...

set nat disable option ...

Enable and disable nat options.

The following options are supported:

log

Enable statistics logging.

Default is disable.

incoming

Allow unknown incoming packets to pass.

Default is enable.

same-ports

Try to use same ports while aliasing.

Default is enable.

unreg-only

Enables aliasing only for unregistered networks.

Default is disable.