Mikrotik script to update a dynamic DNS host and IPsec policy

ddns_update

##############Script Settings##################
:local DDNSUser "username"
:local DDNSPass "password"
:local DDNSDomain "yourhost.ddns.net"
:local DDNSServer "https://members.dyndns.org/v3/update"
:local WANInter "pppoe-out1"
###############################################

: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 $DDNSDomain] != $NewIP) do={
      /tool fetch mode=https user=$DDNSUser password=$DDNSPass url="$DDNSServer\3Fhostname=$DDNSDomain&myip=$NewIP" keep-result=no
      :log info "DDNS Update: $DDNSDomain - $NewIP"
      :log info "IPsec: Updating IPsec Policy."
      /ip ipsec policy set [find comment="myIPsec"] sa-src-address=$NewIP
      :log info "IPsec: IPsec Policy updated."
     }
   } 
}

Hello, what version of RouterOS is this for? Will it work with 6.37.x? Thanks.

Yes, it should work fine.