Unstable VPN Site2Site Connection UTM to Cisco RV-042

Hi, Maxi, and welcome to the UTM Community!

Is your problem the TTL for the FQDN?  Does the UTM's IPsec log indicate that it continues to call the same IP?

Cheers - Bob

Hi Bob,

thanks for getting an idea. Indeed it seems like a problem with TTL, because the UTM don't get the new remote dyndns-IP from the remote Ciscorouter. But for better understanding my setup, i`ll put some pictures here. I hope you can see, when the connection is astablished once by hand, it works very good. But the thirst time the remote Router gets an new IP and send this to dyndns.com, no connection is established. After rebuild the connection manualy in the remote Cisco, it continoues to work. Did you see an error in my config (or am i blind to see it).

Thanks for help.
maxi T

Hi Bob,

thanks for getting an idea. Indeed it seems like a problem with TTL, because the UTM don't get the new remote dyndns-IP from the remote Ciscorouter. But for better understanding my setup, i`ll put some pictures here. I hope you can see, when the connection is astablished once by hand, it works very good. But the thirst time the remote Router gets an new IP and send this to dyndns.com, no connection is established. After rebuild the connection manualy in the remote Cisco, it continoues to work. Did you see an error in my config (or am i blind to see it).

Thanks for help.
maxi T

In the Dyn management console, set the TTL to some small number like 15 (15 seconds).
Cheers - Bob

Hi Bob,
thank you for answering. After a long research i have found the problem. The cisco router (with latest firmware) is unable to refresh his dydns-ip automaticly !! Such a worst thing. They have this problem since 2011! NO comment.

Cheers maxi T

Check with Dyn. They have a client that you can run inside the other network that will update DynDNS.
Cheers - Bob