Joachim: Created page with "= DynDNS = Recently dyndns updates on external IP changes did not always work. This should make it more robust. IP from fritzbox taken from https://wiki.ubuntuusers.de/Fritz..."

2020-07-30T10:29:35Z

Created page with "= DynDNS = Recently dyndns updates on external IP changes did not always work. This should make it more robust. IP from fritzbox taken from https://wiki.ubuntuusers.de/Fritz..."

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= DynDNS =

Recently dyndns updates on external IP changes did not always work. This should make it more robust.

IP from fritzbox taken from https://wiki.ubuntuusers.de/FritzBox/Skripte/

== Read external IP from Fritzbox ==

/usr/local/bin/fb-ip.sh

<pre>
#!/bin/bash

if [ "$1" == "" ]; then
FB="fritz.box"
else
FB="$1"
fi

curl "http://${FB}:49000/igdupnp/control/WANIPConn1" \
-H "Content-Type: text/xml; charset="utf-8"" \
-H "SoapAction:urn:schemas-upnp-org:service:WANIPConnection:1#GetExternalIPAddress" \
-d "<?xml version='1.0' encoding='utf-8'?>
<s:Envelope
s:encodingStyle='http://schemas.xmlsoap.org/soap/encoding/' xmlns:s='http://schemas.xmlsoap.org/soap/envelope/'>
<s:Body>
<u:GetExternalIPAddress xmlns:u='urn:schemas-upnp-org:service:WANIPConnection:1' />
</s:Body>
</s:Envelope>" \
-s | grep -Eo '\<[[:digit:]]{1,3}(\.[[:digit:]]{1,3}){3}\>'
</pre>

== Compare external IP with DNS entry ==

/usr/local/bin/check-ip.sh

<pre>
#!/bin/bash

if [ "$1" == "" ]; then
CN="banzhaf.chickenkiller.com"
else
CN="$1"
fi

if [ "$2" == "" ]; then
FB="fritz.box"
else
FB="$2"
fi

XIP=`/usr/local/bin/fb-ip.sh "$FB"`
DIP=`dig +short "$CN"`
if [ "$XIP" == "$DIP" ]; then
echo "OK"
exit 0
fi
echo "ERROR"
exit 1
</pre>

== Update DynDNS if external IP does not match DNS entry ==

if there is a mismatch between external IP and DNS, give it some time and then fix it

/usr/local/bin/ensure-ip.sh

<pre>
#!/bin/bash

DELAY_S=120

if [ "$1" == "" ]; then
CN="banzhaf.chickenkiller.com"
else
CN="$1"
fi

if [ "$2" == "" ]; then
FB="fritz.box"
else
FB="$2"
fi

if ! check-ip.sh "$CN" "$FB" >/dev/null; then
echo "Check IP failed. Waiting to settle"
SINCE=$SECONDS
while [ $((SECONDS - SINCE)) -lt $DELAY_S ]; do
sleep 1
if check-ip.sh "$CN" "$FB" >/dev/null; then
echo "Check IP recovered."
exit 0
fi
done
echo "Check IP still fails. Updating DNS"
update-dns.sh
SINCE=$SECONDS
while [ $((SECONDS - SINCE)) -lt $DELAY_S ]; do
sleep 1
if check-ip.sh "$CN" "$FB" >/dev/null; then
echo "IP updated."
exit 0
fi
done
echo "Updating DNS failed"
exit 1
fi
</pre>

Fritz Box External IP - Revision history

Joachim: Created page with "= DynDNS = Recently dyndns updates on external IP changes did not always work. This should make it more robust. IP from fritzbox taken from https://wiki.ubuntuusers.de/Fritz..."