Telia 4G site to site vpn no traffic

ITB_Tony

I have a customer that have Telia 4G access on one USG60 that we have setup site to site vpn to another USG60. It have worked just fine until a few days ago. The VPN tunnel opens up, but no traffic go in the tunnel, both USG send
Recv:[HASH][NOTIFY:R_U_THERE_ACK]
Recv:[HASH][NOTIFY:R_U_THERE]
Send:[HASH][NOTIFY:R_U_THERE_ACK]
but no traffic inbound on any USG.

Nothing are modified in the USG´s

When we change and setup Telia adsl on Wan1 the tunnel works just fine.
But not work on Telia 4G on Wan1.
anyone have the same problem, or have any idé?

mMontana

-Knock on Telia asking "are you blocking IPSec connections"?
-Does USG60 "on the other side" knows that the "telia side" has dynamic IP addresS?
-Does the "telia side" have the "nailed up" option active and the "other side" has disable that option?

Zyxel_Vic

Hi @ITB_Tony
Not sure which parameter had been changed on Telia 4G service, from the log it seems the DPD can send and receive, so maybe you can try to adjust the MTU size and see if it helps (maybe change to 1300 bytes firstly)