CODEWITHSUNDEEP
linuxunixubuntusshvpn
Spyder
Spyder

Reputation: 109

Linux/Unix check if VPN connection is Active/Up

I have a code which detects if OpenVPN connection is up or down:

if echo 'ifconfig tun0' | grep -q "00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00"
then
echo "VPN up"
else
echo "VPN down"
fi
exit 0

now I'm trying to re-write the code to work with PPTP or IPSEC connection. I've tried to do:

if echo 'ifconfig ppp0' | grep -q "00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00"

or the same with ipsec but does not work. Is there any other way to detect PPTP or IPSEC connection?

Upvotes: 7

Views: 52091

Answers (5)

pioupiou
pioupiou

Reputation: 946

You can also check with the nmcli command, to check if VPN is running or not.

nmcli c show --active | grep vpn

Upvotes: 4

user2909180
user2909180

Reputation: 215

ip route list table 220 if Ip address shown -> VPN connection established, none -> no VPN

or

if [ "0" == ifconfig | grep wlan0 | wc -l ]; then echo "NO wlan0 has no VPN"; else echo "YES wlan0 has VPN"; fi

Upvotes: -2

labatman
labatman

Reputation: 31

The following script will:

  • Run the ISPConnectivity.sh script every 5 minutes. This will mean that the VPN tunnel will not be down for more than 5 minutes.
  • Check if the tun interface is down, and start the vpn script if it is.
  • Check connectivity if the tun0 interface is up. It does ping tests on 2 Public IPs (if I get even a single response from 1 of the IPs tested, I consider this a success ), and all have to fail to run the vpn script. I ran ping tests on multiple hosts to prevent the vpn script from starting in case the ping test failed on 1 IP.
  • Send all failure output to a file in my home directory. I do not need to see if any test succeeded.

Contents of sudo crontab:

*/5 * * * * /home/userXXX/ISPConnectivity.sh >> /home/userXXX/ISPConnectivity.log 2>&1

Contents of ISPConnectivity.sh script:

#!/bin/bash 

# add ip / hostname separated by white space
#HOSTS="1.2.3.4"
HOSTS="8.8.8.8 4.2.2.4"
# no ping request
totalcount=0
COUNT=4

DATE=`date +%Y-%m-%d:%H:%M:%S`

if ! /sbin/ifconfig tun0 | grep -q "00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00"
then
        echo $DATE      tun0 down
        sudo /home/userXXX/startVPN.sh start
else

        for myHost in $HOSTS;
        do
                count=`ping -c $COUNT $myHost | grep 'received' | awk -F',' '{ print $2 }' | awk '{ print $1 }'`
                totalcount=$(($totalcount + $count))
        done

        if [ $totalcount -eq 0 ]
        then
                echo $DATE      $totalcount "fail"
                sudo /home/userXXX/startVPN.sh start
        #else
        #       echo $DATE      $totalcount "pass"
        fi
fi

Upvotes: 3

Spyder
Spyder

Reputation: 109

I'm actually looking into more flexible solution eg:

MyIP=$(curl http://api.ipify.org/?format=text)
if [ "$MyIP" != "MYORYGINALIP" ]
then
    echo "IPSEC VPN is Running -  " $MyIP
else
    echo "IPSEC VPN is Not Running - " $MyIP
fi
exit 0

what about that? can I improve it any way?

Upvotes: 0

larsks
larsks

Reputation: 311606

That echo statement is erroneous. As @unwind says, the single quotes (') should be backtics (`). Your current code is sending the literal value ifconfig ppp0 to grep, which doesn't do anything useful.

But you don't actually need the backtics, either. You can just send the output of ifconfig to grep directory; using echo doesn't get you anything:

if ifconfig ppp0 | grep -q "00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00"; then
  echo ppp connection is up
fi

Upvotes: 3

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