Check network connectivity in DOS

Complicated question to answer, since it is possible to have multiple NICs in a computer, and each one could be connected to a network.  Also, need to define what "connected to a network" means.  You could be plugged into a switch, and have an autoconfiguration address assigned, which may or may not meet your definition of "connected to a network" depending on how your network is defined.

One simple approach is to just ping something that you expect to be reachable.  In a corporation, maybe your local DNS server.  At home, maybe your router.  For an internet-connected system, maybe a public DNS server:

ping.exe -n 1 ip.to.test.here >nul
if errorlevel 1 goto NoConnection
...

Id suggest that if the connectivity works one can assume the adapter is up. Without connection the adapter would be unable to report back regardless that it is up. So a ping as per above suggestions should suffice.

Just tried this and the !state! is always up, even if I cannot ping the !ipaddress!, unplug the network cable

for /f "tokens=5,7" %%a in ('ping -n 1 !ipaddr!') do (
    if "x%%a"=="xReceived" if "x%%b"=="x1," set state=up

were you trying just that statement or the whole script?  The preceding line setting state=down as default,  you may need that

I tried - it worked for me

I think the problem is when I ping I still get Received packages. i.e from the ping I get "Destination host unreachable" Sent = 4, Received = 4, Lost = 0 (0% Loss)

I can see your point - I modified the code a bit -  namely,
for /f "tokens=4" %%a in ('ping -n 1 !ipaddr!') do (
if "%%a"=="bytes=32" set state=up

:: Checking adapter status
@setlocal enableextensions enabledelayedexpansion
@Echo Off
For /f "skip=2 tokens=1,2,3,*" %%a In ('NetSh Int Show Int') Do (
	if %%b==Connected call :Up "%%d"
)
Exit /B

:Up
@echo Adapter %1 is up
:: Check connectivity
set ipaddr=10.2.2.2
:loop
set state=down
for /f "tokens=4" %%a in ('ping -n 1 !ipaddr!') do (
    if "%%a"=="byte=32" set state=up
)
echo.Link is !state!
ping -n 6 127.0.0.1 >nul: 2>nul:
if !state! == up goto :mapdrives
goto :loop
endlocal
:mapdrives

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Thanks, also I noticed that the following does not seem to work for windows xp

For /f "skip=2 tokens=1,2,3,*" %%a In ('NetSh Int Show Int') Do (
      if %%b==Connected call :Up "%%d"
)

When I ran "Netsh int show int" I don't get anything in the State column, it is just empty

Netsh was in its infancy with Windows XP.  The command syntax was a bit different than the current generation.  I don't have an XP machine accessible to test out - try "netsh int sh adapters"

You may want to try VBscript of WMI to deal with XP

Thanks found another way using WMIC