Dynamic DNS Update Script for No-IP DNS (MikroTik Router OS)

To update the DNS IP to NO-IP DNS, follows the following step:
1. Create a new script named no-ip_ddns_update
The following permissions are required for this script to run:

• write
• test
• read

2. Paste the source code that appears below. Edit the user, password, hostname and interface info to match your setup.

# No-IP automatic Dynamic DNS update
#--------------- Change Values in this section to match your setup ------------------
# No-IP User account info
:local noipuser "your_no-ip_user"
:local noippass "your_no-ip_pass"
# Set the hostname or label of network to be updated.
# Hostnames with spaces are unsupported. Replace the value in the quotations below with your host names.
# To specify multiple hosts, separate them with commas.
:local noiphost "hostname.no-ip.net"
# Change to the name of interface that gets the dynamic IP address
:local inetinterface "your_external_interface"
#------------------------------------------------------------------------------------
# No more changes need
:global previousIP
:if ([/interface get $inetinterface value-name=running]) do={
# Get the current IP on the interface
   :local currentIP [/ip address get [find interface="$inetinterface" disabled=no] address]
# Strip the net mask off the IP address
   :for i from=( [:len $currentIP] - 1) to=0 do={
       :if ( [:pick $currentIP $i] = "/") do={
           :set currentIP [:pick $currentIP 0 $i]
       }
   }
   :if ($currentIP != $previousIP) do={
       :log info "No-IP: Current IP $currentIP is not equal to previous IP, update needed"
       :set previousIP $currentIP
# The update URL. Note the "\3F" is hex for question mark (?). Required since ? is a special character in commands.
       :local url "http://dynupdate.no-ip.com/nic/update\3Fmyip=$currentIP"
       :local noiphostarray
       :set noiphostarray [:toarray $noiphost]
       :foreach host in=$noiphostarray do={
           :log info "No-IP: Sending update for $host"
           /tool fetch url=($url . "&hostname=$host") user=$noipuser password=$noippass mode=http dst-path=("no-ip_ddns_update-" . $host . ".txt")
           :log info "No-IP: Host $host updated on No-IP with IP $currentIP"
       }
   }  else={
       :log info "No-IP: Previous IP $previousIP is equal to current IP, no update needed"
   }
} else={
   :log info "No-IP: $inetinterface is not currently running, so therefore will not update."
}

3. Create a new scheduler entry to run this script every 5 mins.

/system scheduler add comment="Update No-IP DDNS" disabled=no interval=5m \
name=no-ip_ddns_update on-event=no-ip_ddns_update policy=read,write,test

Alternative script.

Alternative script uses DNS Resolve and is based on an documentation http://wiki.mikrotik.com/wiki/Manual:Scripting-examples and documentation No-IP DNS Update API http://www.no-ip.com/integrate/request
Can be modified for use with other Dynamic DNS services supported ReST API.

##############Script Settings##################
:local NOIPUser "no-ip.com LOGIN"
:local NOIPPass "no-ip.com PASSWORD"
:local WANInter "MikroTik Router WAN Interface Name"
###############################################
:local NOIPDomain "$NOIPUser.no-ip.org"
:local IpCurrent [/ip address get [find interface=$WANInter] address];
:for i from=( [:len $IpCurrent] - 1) to=0 do={
  :if ( [:pick $IpCurrent $i] = "/") do={
    :local NewIP [:pick $IpCurrent 0 $i];
    :if ([:resolve $NOIPDomain] != $NewIP) do={
      /tool fetch mode=http user=$NOIPUser password=$NOIPPass url="http://dynupdate.no-ip.com/nic/update\3Fhostname=$NOIPDomain&myip=$NewIP" keep-result=no
      :log info "NO-IP Update: $NOIPDomain - $NewIP"
     }
   }
}

Note:
:local NOIPDomain “$NOIPUser.no-ip.org“ – True if the username is the third level domain and is registered in the domain *. no-ip.org(example: username=testuser1 and domain=testuser1.no-ip.org). In another case, the string to be changed.
The symbol “\3F” is used to replace the shielded symbol “?” in the URL.
Tested to work on RouterOS 5.21.
Sample configuration:

##############Script Settings##################
:local NOIPUser "testuser1"
:local NOIPPass "testpassword"
:local WANInter "ether1"
###############################################

If you use another WAN-interface, use it(example: pppoe-out1, pptp-out1, l2tp-out1).