RUT955 ipsec with Fortigate

[adito]

dear community . we are have RUT and configuratin with VPN ipsec to fortigate using allow all trafic
the connection for tunneling already estabilis but i cant do ping to fortigate or local network.
are in this communitu have some problem with me? and how to solve this?

[Daumantas]

Hello,

As I understand, both Phase 1 and Phase 2 communication establishes, but you are not able to reach the remote subnet, correct? Are you able to ping the RUT955 LAN IP from the Fortigate?
If that is the case, I’d recommend lowering the MTU of the mobile interface. This can be done by navigating to Network → Interfaces → General, editing the mob1s1a1 interface (if SIM1 is used), and in the advanced settings changing the Override MTU option to 1250. If this helps, MTU can be raised to 1420 and re-checked.
Additionally, make sure that the firewall rules on the FortiGate are configured correctly and allows the traffic to pass through.

Best regards,