we have a Customer who who has a remote Branch Office, They have connected the remote branch using ISP Media via Fiber(I mean an Ethernet Cable is connected from L3 Switch at main Office to the CP of ISP and Similarly an Ethernet Cable is connected from the CP to the L2 Switch at Branch Office, and in between CPs They are using Fiber optic). The LAN of Main Office is easily accessible using Cisco or TP-Link Switches or directly connecting the PC but not accessible using Summit X440-G2-L2 Switch.
The most interesting thing is that we connect an 8-Ports Cisco normal switch with CP and connect our X440-L2 with that Switch it start working, after that we remove this 8-Ports Cisco switch from the middle and connect our Summit X440-L2 switch directly with CP and it start working fine but after a month there comes some power outage and it stop working again.
Now we are trying the same techniques again and again and it is not working.
Kindly help us about the Solution please