IPSEC Site to Site -Frequent Tunnel Down after every ISP IP changes

[Ashik_Sheik]

Hi

We have many branches connected to HO by IPSEC .The Branch is dailing to HO because only HO device is having Static IP and Branch doesn't .

This was successfully working until we upgrade the branch devices to 5.6 .After the upgrade whenever ISP IP changes the tunnel goes down then we have to restart the branch fortigate device to bring the tunnel up.

If anyone faced such issues and got work around please let me know .

Regds

Ashik