disconnections.bat

@echo off
echo === DNS and LAN connectivity monitoring started : %date% %time% ===
echo === DNS and LAN connectivity monitoring started : %date% %time% === >> dc.txt
:int
ping 8.8.8.8 -n 1 > NUL &rem This IP is Google's DNS server, replace it by the one you need to test
if %errorlevel% EQU 0 (
        set global=1
) else (
        set global=0
)

ping 192.168.1.1 -n 1 > NUL &rem Replace this IP by your router address
if %errorlevel% EQU 0 (
        set local=1
) else (
        set local=0
)

ping -n 4 127.0.0.1 >nul &rem only used as a 4s delay

if %global% EQU 0 (
    if %local% EQU 1 (
        echo DNS Dysfunction : %date% %time%
        echo DNS Dysfunction : %date% %time% >> dc.txt
    )
)
if %local% EQU 0 (
    echo LAN Dysfunction : %date% %time%
    echo LAN Dysfunction : %date% %time% >> dc.txt
)
if %global% EQU 1 (
    echo OK : %date% %time%
)
goto int