IPsec - Site to Site Problem - Green but no traffic

Hi Thomas,

Thank you for reaching out to Sophos Community.

Have you tried to use any how-to videos, documentation, Sophos Assistant, or KBA to try to check the issue?

Can you share any error logs?

To troubleshoot the issue, you may refer to the below link and start saving the logs to find the root causing the issue if the issue re-occurs.

https://support.sophos.com/support/s/article/KB-000038566?language=en_US

Hey Erick,
Yes i Have Chekced the troubleshoot. but nothing of the describet problem is matching my problem exact.

The VPNs suddenly stops working. in the logs is no error or something else.

unt /log/stronswan.log is nothing shown.
it happen suddenly on single vpns and not on all. (i have 25 tunnels)

Both Tunnels say they are "green". but the log is stopped and the the gateways on the oter site ar not reachable.

I cannot even the tunnelinterfaces ping.

Hey Erick,
Yes i Have Chekced the troubleshoot. but nothing of the describet problem is matching my problem exact.

The VPNs suddenly stops working. in the logs is no error or something else.

unt /log/stronswan.log is nothing shown.
it happen suddenly on single vpns and not on all. (i have 25 tunnels)

Both Tunnels say they are "green". but the log is stopped and the the gateways on the oter site ar not reachable.

I cannot even the tunnelinterfaces ping.

Hello Thomas,

try to disable ipsec acceleration on the firewalls:

https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/CommandLineHelp/DeviceConsole/SystemCommands/index.html#firewall-acceleration

Steps:

To disable the IPsec acceleration from the console (menu 5, then 4) of the Sophos Firewall:

console> system ipsec-acceleration show

console> system ipsec-acceleration disable

Hey Philipp

I assume that I have to make the settings on both sides of the VPN connection, or is it enough to make them on one firewall?

I would start with the 19.0 system and see if it helps.

I have made the settings.
But I have to correct the sequence of numbers on the console.

You only have to press 4 to be able to enter the commands.

Unfortunately, I have a long response time here, as the failures were not present all the time.

Thank you very much and greetings from germany
Thomas

Sorry for giving the wrong menus. It was out of memory, did not check with current version 19.x.

Is it working now?

Just by chance: is the one malfunctioning VPN site connected via an other provider like Net Cologne or Vodafone/Unitymedia and all others use Telekom or an other single ISP?