you need to tell the registrar / company you bought your domain from [name.com?] that 184.108.40.206 is an authoritative source of information for concretex.com.
and.. in most cases you'll need to have at least two dns servers, not just one. you can use free dns like this one to be your secondary dns.
usually you'll have to have to provide host names [rather than ip address] together with ip addreses for your name servers.at name.com you'll delegate concretex.com to the following address:
- ns1.concretex.com / 220.127.116.11
- ns0.xname.org [ or ns1 or ns2 - check this ]
on your own server 18.104.22.168 you'll have to create basic dns record for concretex.com zone - something that will contain at least:
@ IN NS ns1.concretex.com. ; yes it's a dot at the end and it's correct
@ IN NS ns0.xname.org.
ns1 IN A 22.214.171.124
www IN A 126.96.36.199
; and probably more
you'll have to configure your bind to allow zone transfer to the name servers of xname.org [ you'll find the list of their source ips here ]. to prevent abuse: