IPsec tunnel use private IP to negotia

[rozkie20]

Hello Checkmates,

We have recently set up a Site-to-Site VPN for our Quantum Spark deployment to replace the Internet Leased Line. We are using two CP1555 gateways in centrally managed mode. One gateway (Local Gateway) connects to the SMS using a private IP (10.17.30.6), and the other gateway (Remote Gateway) connects to the SMS using a public IP.

Both sites are still connected through an Internet Leased Line.

During the initial VPN setup, both gateways use the correct public IPs for negotiation. However, once we disable the Leased Line routes, after about 30 minutes the Local Gateway starts using its private IP to negotiate with the Remote Gateway. As a result, the VPN tunnel comes up initially but then goes down after approximately 30 minutes.

In Link Selection, we have already selected the public IP, but we do not understand why the gateway still switches to the private IP for VPN negotiation.

Anyone have experience about this issue can you share with me to fix.

[AkosBakos]

Hi,

Maybe it is a trivial answer, but when an interface become down, the assigned routes will be off. 

Compare the two routing table (when works, and when not)

Akos