ipsec problom

[sephd]

hello all

i configured ipsec that 90% of time is working well till its suddenly stop working
from what i can see phase1 and phase2 are up and connected , SADs and SPDs look ok
in wireshark i do see packets coming from the remote site.

i cant ping hosts at remote side
from cli i do traceroute with source ip of LAN nic to the hosts at remote site but i see its going to the internet , i expeted to see as in fortigate something like 3 hops .
same issue happen last week after half day it start working again without doing anything.

anyways will appreciate your help to understand whats going on and how to debug this
i need to understand where is the problem on my side or remote side