opendns-updater

Updater for OpenDNS

A straightforward bash script to automatically update your dynamic IP address with OpenDNS.

# Quick OpenDNS IP updater
user="home@example.com"
pass="secretpass"
host_label="home-internet"

# grab current public IP
cur_ip=$(curl -s https://api.ipify.org)

# files for storing previous IP and logs
prev_ip_file="$HOME/.opendns_last_ip"
logfile="$HOME/opendns_log.txt"

# read last known IP if exists
if [ -f "$prev_ip_file" ]; then
    prev_ip=$(cat "$prev_ip_file")
else
    prev_ip=""
fi

# if IP changed, tell OpenDNS
if [ "$cur_ip" != "$prev_ip" ]; then
    echo "$(date): Whoa! IP changed from $prev_ip to $cur_ip. Sending update..." >> "$logfile"
    curl -u "$user:$pass" "https://updates.opendns.com/nic/update?hostname=$host_label&myip=$cur_ip"
    echo "$cur_ip" > "$prev_ip_file"
else
    echo "$(date): IP stayed the same, nothing to do." >> "$logfile"
fi

How it works

Checks your current external IP address.
Compares it with the last recorded IP.
Updates OpenDNS if the IP has changed.
Logs updates with timestamps.

Needs

macOS
OpenDNS account

How to install

Clone the repository:

git clone https://github.com/hexpad/opendns-updater.git
cd opendns-updater

Make the script executable:
```
chmod +x opendns_updater.sh
```

Launch the script, then type your OpenDNS login information

nano opendns_updater.sh

After editing the lines below, save and exit:

USERNAME="your-email@example.com"
PASSWORD="your-password"
LABEL="home-internet"

View the log file

Use the open . command to access the log file location.

Sun Apr 20 11:59:01 +03 2025: IP changed: 140.171.118.36 → 226.196.65.78

Cron Job (Automatic Execution)

The script can be run automatically with cron Check your current terminal path:

pwd

Add cronjob

echo '* * * * * /bin/bash /your/path/opendns_updater.sh' | crontab -