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Configuring Address Pools for Network Address Port Translation (NAPT) Overview


With Network Address Port Translation (NAPT), you can have up to 4096 network address or port translations.

The port statement specifies port assignment for the translated addresses. To configure a specific range of port numbers, include the port range low minimum-value high maximum-value statement at the [edit services nat pool nat-pool-name] hierarchy level.

Junos OS for ACX Series routers allocates ports sequentially—that is, ACX Series routers allocate the first available address or port from the NAT pool.

The NAT pool called napt in the following configuration example uses the sequential implementation:

Endpoint Independent Flow for NAPT

Endpoint independent flow ensures the assignment of the same external address and port for all connections from a given host or port to any destination. This means if the address or port are from a different source, you are free to assign a different external address.