Contents

How to configure Basic NAT on Versa FlexVNF CPE.. ..........................................................................................................................................1

Introduction......................................................................................................................................................................................................................... 1

Prerequisites.........................................................................................................................................................................................................................1

Configuring CGNAT Pool.................................................................................................................................................................................................2

Configuring CGNAT Rule................................................................................................................................................................................................ 3

Results:................................................................................................................................................................................................................................... 4

This article describes how to configure the Basic NAT in versa CPE

Introduction

Basic-NAT is IP to IP translation, source IP-address of a packet into another IP address statically.

Basic NAT is also a bidirectional NAT, which we create a NAT entry even when initiating the traffic from outside to inside.

Here we have shown that to configure the basic NAT on Versa FlexVNF.

In this example, 

1. Traffic originating from inside to out, with source address 10.10.201.0/24 of the packet translated to10.30.201.0/24. 
2. If the traffic is initiated from outside, destined to 10.30.201.0/24, will be translated to 10.10.201.0/24

Prerequisites

1. The reachability should be there from FlexVNF WAN interface to remote Host or internet.
2. CGNAT service should be enabled on Versa FlexVNF CPE.
3. Required routing in LAN-VR to forward traffic towards correct wan transport (for DIA configured KB Link https://support.versa-networks.com/a/solutions/articles/23000020672)

Configuring CGNAT Pool

1. In the Appliance context view, go to Configuration > Services > CGNAT>  Pool: click + to add a pool. 
2. You can define Nat pool as subnet or host IP, here we configure subnet 10.30.201.0/24
3. Egress Interface/Networks is not recommended for basic-nat/
4. Select the routing instance, where you want the packet to be forwarded after natting.

Configuring CGNAT Rule

1. To create the rule, go to Configuration > Services > CGNAT> Rule > click+ to add the rule.
2. Configure the actual source subnet as source IP, select the Source Zone, set the source routing-instance under the match condition. The rule should be as specific as policy.
3. Under the action, select the translation as Basic-NAT-44 and select the Natted pool.
4. If you have configured any DIA, increase the precedence value of this Basic-NAT rule.

Results:

To Check the NAT session.

Traffic Can be initiated from Outside to Inside.