Hi,
I have been using next-server a lot without issue. But I have many thinclients / phones / deployment scripts running on different servers. I try to recreate the next-server behaviour via option running on the lastest 7.17 RouterOS. So I can lease define my option 66/67
I created an option 66 using my IP converted into 0x format (192.168.92.250) to value=0xc0a85cfa.
I also try add code=66 force=yes name=thinBoot_Server value=“‘192.168.92.250’”
So far this doesn’t work when I assign this to a static lease. 
Anyone successful on a similar setup? Or have a solution not involving vlans / brodcast domain?
Rock.