I have seen it for a long time. After integrating the opinions from the upper floor, I finally tried to write it like this:
@echo off
set a=100
:loop
set /a a+=1
::start cmd /c &echo %a% >>%a%.txt
start cmd /c "ping -n 1 192.168.2.%a%&&echo 192.168.2.%a% >>ip.txt"
if "%a%"=="105" exit
goto :loop
@echo off
set a=100
:loop
set /a a+=1
::start cmd /c &echo %a% >>%a%.txt
start cmd /c "ping -n 1 192.168.2.%a%&&echo 192.168.2.%a% >>ip.txt"
if "%a%"=="105" exit
goto :loop