How to configure Mikrotik DHCP Server for Cisco Phone TFTP option
1- Change your TFTP server IP in to hex code
you can use this online tool : http://www.miniwebtool.com/ip-address-to-hex-converter/
2- Now configure Mikrotik RouterOS :
/ip dhcp-server option add code=150 name=ciscotftp value=0xC0A80307
3- Add this on DHCP server Network option on your
Source link
http://xenhelp.blogspot.com/2017/06/mikrotik-routeros-set-custom-tftp.html