IPSec established, I can ping from both site but traffic timeout

[lmu]

Hi,

I would like to created a IPSec with a fird party routeur Swisscom Centro Business 2.0 (alias ADB Italia ST6840) between to location (site) A and B.

Site A is the fird party and site B is the pfsense

• The tunnel is up successfully
• I'm able to ping from site A to the site B and versa from site the B to the site A.
• If from the site B, I try to open the web gui of the routeur based on the site A, I will get the message the page cannot displayed, timeout. I cannot copy file or anything. I'm just able to ping.
• What surprise me from the site A, I'm able to get the webgui of the pfsense based on the site B. I can explore the files for exemple, but I cannot transfert anything, I will get an timeout.

What I discover … if I modify on Pfsense the setting "NAT Traversal" in phase I to "Force" (reload, make the tunnel down then up) then coming back to "auto" (reload, make the tunnel down then up), my tunnel will work for 5 minutes from both sides.

I have 2 pfsense connected to this router, 1 working well since the beging and 2 have the same issues, all settings are identic.

Any help will be greatfull.

regards,
laurent