NAT Pool Addresses

Before TNSR can perform any type of NAT, an inside and outside interface must be set and at least one outside/external address (e.g. WAN-side) must be listed in a NAT pool. These pools are added from configure mode (Configuration Mode) in the TNSR CLI (Entering the TNSR CLI).

Note

TNSR will respond to ARP and ICMP echo requests (ping) for addresses in NAT pools, even when they are not configured on interfaces. Ensure that NAT pool addresses are not used by other hosts on the network.

Warning

These options cannot be changed while NAT is disabled. Enable NAT before running these commands (Enable NAT).

Single NAT Pool Address

For a single external address, define a NAT pool like so:

tnsr(config)# nat pool addresses 203.0.113.2

Note

This can be an IP address configured directly on an interface, but that is not a requirement.

Multiple NAT Pool Addresses

For multiple addresses, there are two methods: Using a range, or repeating the command with single addresses.

First, using a range:

tnsr(config)# nat pool addresses 203.0.113.2 - 203.0.113.6

Note

NAT pools are defined as single addresses or contiguous ranges. It is not possible to remove or exclude addresses from within a pool configured as a range; The entire range must be removed by using the starting address. To exclude addresses in the middle of a range from use in NAT pools, use multiple discrete pools with ranges that do not include the undesirable addresses.

The range command can be repeated to define multiple ranges:

tnsr(config)# nat pool addresses 203.0.113.2 - 203.0.113.3
tnsr(config)# nat pool addresses 203.0.113.5 - 203.0.113.6

Repetition of the single entry form for each pool address also results in multiple pool entries:

tnsr(config)# nat pool addresses 203.0.113.2
tnsr(config)# nat pool addresses 203.0.113.3
tnsr(config)# nat pool addresses 203.0.113.5
tnsr(config)# nat pool addresses 203.0.113.6

NAT Pool Interfaces

TNSR also supports using an interface to automatically determine pool addresses:

tnsr(config)# nat pool interface GigabitEthernet0/14/1

For Outbound NAT this is typically the interface set as ip nat outside.