Configuring RNAT with LLB

You can configure an LLB setup for reverse network address translation (RNAT) for outbound traffic. This ensures that the return network traffic for a specific flow is routed through the same path. First configure basic LLB, as described in “Configuring a Basic LLB Setup”, and then configure RNAT. You must then enable use subnet IP (USNIP) mode.

To add SNIPs for ISP routers by using the command line interface

At the command prompt, type:

add IP NS <network><subnet of first ISP in the IP router> <subnet mask> -type SNIP

add IP NS <in the IP subnet of second ISP router> <subnet mask> -type SNIP

Example:

add ns ip 10.140.23.1 255.255.255.0 -type snip

add ns ip 10.141.23.1 255.255.255.0 -type snip

To configure RNAT by using the command line interface

At the command prompt, type:

set rnat <network> <netmask>

show rnat

Example:

set rnat 10.102.29.0 255.255.255.0 -natIP 10.140.23.1
set rnat 10.102.29.0 255.255.255.0 -natIP 10.141.23.1
show rnat
    1) Network: 10.102.29.0      Netmask: 255.255.255.0
     NatIP: 10.140.23.1
     2) Network: 10.102.29.0      Netmask: 255.255.255.0
     NatIP: 10.141.23.1

To configure RNAT by using the configuration utility

1. Navigate to System > Network > NATs.
2. On the RNAT tab, click Configure RNAT.
3. Specify the network on which to perform RNAT.

Note

You can also configure RNAT by using Access Control Lists (ACLs). Refer Configuring RNAT for details.

To enable Use Subnet IP mode by using the command line interface

At the command prompt, type:

enable ns mode USNIP

show ns mode  

Example:

enable ns mode USNIP

show ns mode
        Mode                           Acronym              Status
        -------                        -------              ------
 1)     Fast Ramp                      FR                   ON
 2)     ….
 8)     Use Subnet IP                  USNIP                ON
 9)     …

To enable Use Subnet IP mode by using the configuration utility

1. Navigate to System > Settings and, under Modes and Features, click Configure Modes.
2. In the Configure Modes dialog box, select Use Subnet IP, and then click OK.