Update script for dynv6.com to set your IPv4 address and IPv6 prefix

dynv6.sh

#!/bin/sh -e
hostname=$1
device=$2
file=$HOME/.dynv6.addr6
[ -e $file ] && old=`cat $file`

if [ -z "$hostname" -o -z "$token" ]; then
  echo "Usage: token=<your-authentication-token> [netmask=64] $0 your-name.dynv6.net [device]"
  exit 1
fi

if [ -z "$netmask" ]; then
  netmask=128
fi

if [ -n "$device" ]; then
  device="dev $device"
fi
address=$(ip -6 addr list scope global $device | grep -v " fd" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)

if [ -e /usr/bin/curl ]; then
  bin="curl -fsS"
elif [ -e /usr/bin/wget ]; then
  bin="wget -O-"
else
  echo "neither curl nor wget found"
  exit 1
fi

if [ -z "$address" ]; then
  echo "no IPv6 address found"
  exit 1
fi

# address with netmask
current=$address/$netmask

if [ "$old" = "$current" ]; then
  echo "IPv6 address unchanged"
  exit
fi

# send addresses to dynv6
$bin "http://dynv6.com/api/update?hostname=$hostname&ipv6=$current&token=$token"
$bin "http://ipv4.dynv6.com/api/update?hostname=$hostname&ipv4=auto&token=$token"

# save current address
echo $current > $file

Would be great if this script has a "ipv4 only" option. In the moment it only works if you have a ipv6.

v4 only client
https://gist.github.com/pulsar256/42313fcb2d3ae805805f

Is there a php version or a batch version of this available?

Is there are reason why you use http for the update and not https which you have available?

I used the following php script on my synology webdrive (/sbin/dynv6ddns.php). In addition to the script i updated the /etc/ddns_provider.conf manually with the following provider configuration:

[USER_DynV6]                                                                                              
        queryurl=http://dynv6.com                                                                         
        modulepath=/sbin/dynv6ddns.php 

the dynv6ddns.php:

#!/usr/bin/php -d open_basedir=/sbin
<?php

if ($argc !== 5) {
    echo 'badparam';
    exit();
}

$account = (string)$argv[1];
$hostname = (string)$argv[3];
$ip = (string)$argv[4];

// check the hostname contains '.'
if (strpos($hostname, '.') === false) {
    echo 'badparam';
    exit();
}

// only for IPv4 format
if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
    echo "badparam";
    exit();
}

$url = 'https://dynv6.com/api/update?token='.$account.'&hostname='.$hostname.'&ipv4='.$ip;

$req = curl_init();
curl_setopt($req, CURLOPT_URL, $url);
curl_setopt($req, CURLOPT_RETURNTRANSFER, TRUE);
$res = curl_exec($req);
curl_close($req);

$query='host updated';

if (substr($res,0,strlen($query)) === $query) {
    echo "good";
} else {
    echo $res.'     ';
    echo "update failed";
}

I made a new script for ipv4
https://github.com/zeroskunk/dynv6/blob/master/dynv6.sh

Looking for the mngtmpaddr flag ensures that no privacy extension addresses leak into dynamic DNS.

ip -6 addr list scope global mngtmpaddr $device

See https://gist.github.com/danrl/f568bf6d61acb3d0e9b11986b09deada

Hi, I am having some troubles with this script. I am totally new in scripting and dont know what to write in the console.
I tried this but it didn't work:
sh dynv6.sh token=Q-4pOEg4UyAuq8mySeWgAJfiGWXHtQ ./dynv6.sh test123x.dynv6.net

What should I make different?

@lukasreindl

1. Click on the 'raw' button on the top right-hand side of the above script, and copy/paste the entire code to a file dynv6.sh in your home directory.
2. Make the script executable
   chmod +x dynv6.sh
3. Execute the script using the link found on the 'instructions' tab of your host on dynv6.net
   token=Q-4pOEg4UyAuq8mySeWgAJfiGWXHtQ ./dynv6.sh test123x.dynv6.net

Optionally have cron execute the script every 5 mins or so. Nothing will be sent if your IP hasn't changed.

• crontab -e to open your editor
• Add the line */5 * * * * token=Q-4pOEg4UyAuq8mySeWgAJfiGWXHtQ ./dynv6.sh test123x.dynv6.net
• save and close editor

I run the script on my raspberry pie. It runs fine and updates my ipv4 and ipv6 address.
When I enter the host name at home in my browser everything works. I can login via ssh.
But when I do the same from my machine at work or from my mobile phone with turned off wlan I cannot reach the pie.
Any idea what could be wrong? Does it maybe try to connect via ipv4? The address is set but it will not be able to reach my machine as
I have a dual-stack here.

thanks for both ipv6 and ipv4

If IPv6 address not changed, but the (global) IPv4 address, it wont be updated..

Hi... ip -6 command used in line 19 not working in mac os 10.12 Sierra?!! (indeed not...) I get an error "command not found"

Is it possible to update the records and not the normal domain name? I tried to just append it:
token=xxxxxxxxxxxxx ./dynv6.sh yyyyyy.xxxxxx.dynv6.net

It produced the following error:
curl: (22) The requested URL returned error: 404 Not Found

Would be nice to get a Inadyn-mt example configuration as well for Dynv6 Records. Couldnt find one online.

Hi, im running this on a raspberry Pi behind my ISPs router. Is there a way to use this script to update the external/public IP?

@stoeffel85

Hi, im running this on a raspberry Pi behind my ISPs router. (...)

Is it not working? What error is coming up? Would you please send some more information, please?

Kind regards
//neph

Hi nephilim75,
the script is working nicely, however, the IP that is updated to dyn6c is the raspberrys local ip in my home networt (192.168.0.something).
However, I found a way, I substituted line 19 with
v4_address=$(curl ifconfig.me)

I am running this script on my Raspberry Pi 3.

ifconfig -a
pi@raspberrypi:~ $ ifconfig -a
eth0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether b8:27:eb:49:d4:40 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.15 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::b6bc:2ed3:e647:93b9 prefixlen 64 scopeid 0x20
ether b8:27:eb:1c:81:15 txqueuelen 1000 (Ethernet)
RX packets 290 bytes 25171 (24.5 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 211 bytes 38365 (37.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

When I run the script, I get this output:

pi@raspberrypi:~ $ token= ./dynv6.sh satvam.dynv6.net
no IPv6 address found

Am I doing something wrong here?

The IPv6 "address=…" line gives me the global temporary dynamic IPv6 host address, but what I need for DNS updates is the global dynamic (i.e., MAC-based) host IP, so I use a modified line like this:

address=$(ip -6 addr list scope global permanent dynamic $device | grep -v " fd" | grep -v " temporary" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)

for mac

address=$(ifconfig | grep inet | grep "autoconf temporary" | sed -E -n 's/.*inet6 ([0-9a-f:]+).*/\1/p' | head -n 1)

When I am trying to run

token=Q-4pOEg4UyAuq8mySeWgAJfiGWXHtQ ./dynv6.sh test123x.dynv6.net
With my own Token and hostname I get the following error.

sed: -e expression #1, char 10: unterminated `s' command
no IPv6 address found
Do I need to add a '-e' and If yes. Where do I please need to place it?

Thx,blub4747

@uhardegger Thanks a lot for sharing your script! I've modified it a bit for my Synology router and added system log prints (to /var/log/messages). The modified version can be found here. The corresponding ddns_provider.conf file is uploaded here.

#!/bin/bash

#Configure
Hostname="example.dynv6.net"
IPVERSION="6" #IPV4=4, IPV6=6
UpdateURL="http://dynv6.com/api/update?hostname=$Hostname&ipv6=auto&token=YOUR_TOKEN"

RecordType=$([ "$IPVERSION" == 4 ] && echo "A" || echo "AAAA")

while true; do
 SavedIP=$(dig -$IPVERSION +short $RecordType $Hostname) #check IP which is stored on dynamic DNS
 ActualIP=$(dig -$IPVERSION +short $RecordType myip.opendns.com @resolver1.opendns.com) #get actual IP

 if [ "$SavedIP" != "$ActualIP" ] ; then
	wget -qO- $UpdateURL &> /dev/null
	if [[ $? -ge 0 ]]; then
	 SavedIP=$ActualIP
	fi
 fi

 sleep 5s #run every 5 seconds
done

Very simple and neat script that runs every 5 seconds in a loop. Has some advantages over the script above. Should work on most clients, includes a reliable way to get the IP and can be adapted to most dynamic DNS providers.

Configure hostname, record type and update URL, done.

For dynv6 you have to add your token in the URL. If you want to use IPV4, change IPVERSION to 4 and change url to ipv4 version of the URL. Then, simply copy it into a file like ddnsupdate.sh, chmod +x ddnsupdate.sh to make it executable and execute it from a startup script like rc.local: nohup /home/ddnsupdate.sh > /dev/null 2>&1&

There is example of systemd unit

[Unit]
After=miredo.service
[Service]
ExecStart=/usr/local/bin/ddnsupdate.sh
[Install]
WantedBy=default.target

Adapted findings and requirements from this thread into a n updated (and currently working) script. Depends on ns1.google.com ability to return a TXT record for o-o.myaddr.l.google.com. @Beaving did a similar thing with opendns but it did stop working as the "myip service" has been discontinued.

Script

#!/bin/bash

if [ -z "$DYNV6_HOSTNAME" -o -z "$DYNV6_TOKEN" -o -z "$DYNV6_PROTO" ]; then
  echo "Usage:"
  echo "DYNV6_HOSTNAME=hostname DYNV6_TOKEN=token DYNV6_PROTO=[4|6] $0"
  exit 1
fi;

record=$([ "$DYNV6_PROTO" == 4 ] && echo "A" || echo "AAAA")
resolved=$(dig +short $record $DYNV6_HOSTNAME )
actual=$(dig -$DYNV6_PROTO TXT +short o-o.myaddr.l.google.com @ns1.google.com | tr -d '"')

if [ "$resolved" != "$actual" ] ; then
  if [ "$DYNV6_PROTO" == "4" ] ; then
          curl "http://ipv4.dynv6.com/api/update?hostname=$DYNV6_HOSTNAME&ipv4=$actual&token=$DYNV6_TOKEN"
  fi

  if [ "$DYNV6_PROTO" == "6" ] ; then
          echo curl "http://ipv6.dynv6.com/api/update?hostname=$DYNV6_HOSTNAME&ipv6=$actual&token=$DYNV6_TOKEN"
  fi
fi

Example:

DYNV6_HOSTNAME=ramalamadingdong.dynv6.net DYNV6_TOKEN=muchSecureSoSecret DYNV6_PROTO=6 ./update_dns.sh

Please note that if you want to update v6 and v4 records, you will have to call the script twice.

like some other people before me realized: when the ipv6 has not changed, then the ipv4 address is not updated even if it has changed. This is due to 27, 32,40 where the script just exits.

I would open an issue for that if it were not only a gist but a full-fledged github repo. In the meantime - could i just suggest to actually put this script into a full-fledged github repo and to encourage the many people linking to their own versions in the comments here to make an effort and merge their diffs into the script so it actually becoms usable for noobs?

Many thanks for considering this!

I would open an issue for that if it were not only a gist but a full-fledged github repo. In the meantime - could i just suggest to actually put this script into a full-fledged github repo and to encourage the many people linking to their own versions in the comments here to make an effort and merge their diffs into the script so it actually becoms usable for noobs?

+1

Nice service!

I use the following systemd timer/service templates to enable the update on my hosts:

# /etc/systemd/system/dyndns@.service
[Unit]
Description=Update dynv6 DNS Entries

[Service]
Type=oneshot
EnvironmentFile=/etc/conf.d/dynv6
ExecStart=/usr/local/bin/dynv6.sh %I.dynv6.net

[Install]
WantedBy=multi-user.target

# /etc/systemd/system/dyndns@.timer
[Unit]
Description=Minutely dynv6 update

[Timer]
OnCalendar=minutely
Persistent=true

[Install]
WantedBy=timers.target

then enable/start:

sudo systemctl enable dyndns@MYHOSTNAME.timer
sudo systemctl start dyndns@MYHOSTNAME.timer