Versa SDWAN appliances at branch sites can be deployed as an active-active pair, where-in WAN interfaces on one appliance can be used to reach WAN by the other appliance. In such a deployment, the two appliances are connected to each other using an inter-chassis link (ICL). 


The diagram below that illustrates such a deployment with 1 WAN interface on each appliance being shared with the other appliance.
 


In such deployment, Appliance-1 can use the Broadband WAN access-circuit of Appliance-2 to form transport paths to other remote sites with a common transport domain. 
Following configuration is required to achieve this connectivity:


1. On the two appliances connected by inter-chassis link(s), configure "system sd-wan site paired-site location-id <>". The "paired-site location-id <>" value is a free-form string. 

The requirement for "paired-site location-id" value

(a) Both appliances connected by ICL link MUST USE same location-id.
(b) The location-id value MUST NOT be configured on any other SDWAN appliance in the network.It should be unique for each location where the HA pair of FlexVNFs are deployed.
(c) Incase numeric value is used in location-id, It should not overlap with site-id of any other SDWAN appliance in the network, except using the site-id from one of the CPE in same HA as location-id on both(without violating (a) and (b)).          


2. The CGNAT rule configured for performing Source-NAT translation for SD-WAN Overlay traffic(only) ingress on ICL link must be configured with attribute "paired-site true". Active-Active HA deployment from Workflow Template will set the knob to true, no manual change required.

Example1:- Here using site-name combination to distinguish location id
admin@STP601-P-cli> show configuration system sd-wan site | display set | details
set system sd-wan site site-type branch
set system sd-wan site chassis-id KSA3374999
set system sd-wan site site-id 115
set system sd-wan site nat-traversal client interval 2
set system sd-wan site paired-site location-id STP601602
admin@STP602-S-cli> show configuration system sd-wan site | display set | details
set system sd-wan site site-type branch
set system sd-wan site chassis-id KSA3375010
set system sd-wan site site-id 243
set system sd-wan site nat-traversal client interval 2
set system sd-wan site paired-site location-id STP601602

Example2:- Here using site-id from one of the CPE in same HA as location-id on both
admin@STP601-P-cli> show configuration system sd-wan site | display set | details
set system sd-wan site site-type branch
set system sd-wan site chassis-id KSA3374999
set system sd-wan site site-id 115
set system sd-wan site nat-traversal client interval 2
set system sd-wan site paired-site location-id 115
admin@STP602-S-cli> show configuration system sd-wan site | display set | details
set system sd-wan site site-type branch
set system sd-wan site chassis-id KSA3375010
set system sd-wan site site-id 243
set system sd-wan site nat-traversal client interval 2
set system sd-wan site paired-site location-id 115

IMP NOTE: Mis-configuring the paired-site location-id can trigger lot of sdwan neighbor change updates in SD-WAN environment, thus causing increase in flexvnf memory utilization.


 

From VD UI:- Under Workflow>Devices>Add Device(+)> Bind-Data: