GlobalProtect fails to connect to backup gateway when portal is down

[FarzanaMustafa]

Hello,

PAN-OS 8.1.4; GP 4.1.6
I am using only the one VR with dual gateways and ECMP routing enabled with WRR (Weigthed 1/4 (WAN1=50, WAN2=200).

I have one portal configured for WAN2. I have two (2) gateways; one on WAN2 and one on WAN1. When WAN2 is up, I can acces the portal and the gateway on that interface.
When the portal is down (WAN2), and WAN1 up, I expected the client to connect to the second gateway (WAN1) which it does not.

Each of the client's Internet services (WAN1 & WAN2) only have a single public IP address. And they are NATting all traffic in and out to the firewall behind it using private IP addressing.
They have another service listening on TCP 443 (HTTPS). So I need to use a different TCP port for the GP Client.
This I have also configured on my lab PA-VM100 as per the documentation I have found (see below).
The NAT portion of this technique is working to the loopback interfaces if leave the TCP port unchanged (443).
However when I change the port number to any other value (e,g, 10443), it does not work. I cannot browser to access the portal, much less te GP client.

https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClM1CAK

Any idea how to resolve this issue?

[LukeBullimore]

Hey @FarzanaMustafa

The GlobalProtect portal is the termination point that holds all the information about all the available gateways and thus, to connect to a gateway you must first be connected to the portal. If the portal is down there's no way you'll ever be able to connect to the gateway.

Regards,

Luke.