Vyatta NOS documentation

Learn how to install, configure, and operate Vyatta Network Operating System (Vyatta NOS), which helps to drive our virtual networking and physical platforms portfolio.

Multiple Address Ranges for NAT

You can specify the name of a resource address group as the translation address for a NAT rule.

You can create a NAT rule with specific translation addresses, address ranges, or both. Each entry listed in the resource address group is used to create a set of mappings based on the port range.

The number of translation mappings is based on the number of addresses or ports. For address-group entries specified in CIDR format, for example,, the number of addresses is based on the network address and broadcast address. For example, a CIDR of results in an address range of to A single address entry in the address group specifies a single address.

Note: The address range for a CIDR entry does not include the broadcast address or network address.

For resource address groups specified for a NAT rule, the number of address mappings depends on the number and type of address group entries multiplied by the range of ports specified for the rule. If a port range is not specified for the rule, the default port range from 1 through 65535 is used. For example, a NAT rule that specifies a resource address group with two addresses and no port range results in 131,070 mappings.

For source NAT rules, the addresses specified in a resource group are used in ascending numerical order. The next address in the address group is referenced only when all the mappings implied by a resource address group entry have been consumed.

You can also dynamically add and delete address group entries, which takes effect immediately on the next NAT mapping allocations.

Note: IPv6 addresses in resource address groups are ignored.