====== Use Hostnames in Mikrotik Routers ======

Mikrotik routers, like most others, **do not directly support the use of hostnames** instead of IP addresses.

However, we can **use a simple script to resolve a hostname** to an ''address-list'', even if the hostname points to multiple IP addresses.

<note warning>If the '':resolve'' command does not complete normally, the script aborts and you will be left with a bad ''address-list''.</note>

<note warning>As written, this script will not resolve multiple hostnames.</note>

===== Example Scripts =====

==== resolve_delivery.antispamcloud.com ====

:!: This script is intended to resolve multiple hostnames in the ''source='' line.

<file>
/system script
add comment="Resolve DNS Hostname to Address List" name=resolve_delivery.antispamcloud.com owner=admin \
    policy=ftp,reboot,read,write,policy,test,password,sniff,sensitive,romon \
    source=":local hosts {\"delivery.antispamcloud.com\"}\r\
    \n:foreach k,v in=\$hosts do={\r\
    \n  :log info \"Doing \$v\"\r\
    \n  :local listname \$v\r\
    \n  :resolve \$v\r\
    \n  :local iscname [/ip dns cache all find where name=\$v and type=\"CNAME\"]\r\
    \n  :if (\$iscname != \"\") do={\r\
    \n    :local newname [/ip dns cache all get \$iscname data]\r\
    \n    :log info \"\$v is CNAME to \$newname\"\r\
    \n    :set v \$newname\r\
    \n  }\r\
    \n  :resolve \$v\r\
    \n  /ip firewall address-list remove [/ip firewall address-list find where list=\$listname]\r\
    \n  :foreach i in=[/ip dns cache all find where name=\$v and type=\"A\"] do={\r\
    \n    :local ipaddr [/ip dns cache all get \$i data]\r\
    \n    /ip firewall address-list add list=\$listname address=\$ipaddr comment=\$v\r\
    \n    :log info \"IP address: \$ipaddr\"\r\
    \n  }\r\
    \n  /ipv6 firewall address-list remove [/ipv6 firewall address-list find where list=\$listname]\r\
    \n  :foreach i in=[/ip dns cache all find where name=\$v and type=\"AAAA\"] do={\r\
    \n    :local ipaddr [/ip dns cache all get \$i data]\r\
    \n    /ipv6 firewall address-list add list=\$listname address=\$ipaddr comment=\$v\r\
    \n    :log info \"IPv6 address: \$ipaddr\"\r\
    \n  }\r\
    \n}\r\
    \n:log info \"end\""
</file>