registering nameservers

Len Conrad LConrad at
Sun Mar 25 08:19:00 UTC 2001

>Why is it that a machine designated as a nameserver must be registered.

So its A record can be held in the root server(s).  The A record for 
an registered NS host is known as "glue record".

ie, for a domain, the root servers hold the "delegation data" for the 
domain, aka the NS records that are delegated as authoritative for 
the domain.  But you can't go query the NS records unless you know 
the ip for the NS records.  So when the roots "refer" a requesting 
resolver to a domain's NS's, the roots provide both the NS and A 
records, like this:

# dig ns

; <<>> DiG 8.3 <<>> ns
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 4
;;, type = NS, class = IN

;; ANSWER SECTION:              2D IN NS        DNS1.ENOM.COM.              2D IN NS        DNS2.ENOM.COM.              2D IN NS        DNS3.ENOM.COM.              2D IN NS        DNS4.ENOM.COM.

DNS1.ENOM.COM.          2D IN A
DNS2.ENOM.COM.          2D IN A
DNS3.ENOM.COM.          2D IN A
DNS4.ENOM.COM.          2D IN A

4 NS records delegated with authority for the doamin and 4 A records 
as "glue".  Now the resolver can refer to the A records' RDATA to 
query for the domain's other records.

You should see why you can't change the ip of the NS in your zone 
file without first changing the ip of the NS with your registrar / 

>A seperate process from registering a domain name?


>And where is this registeration database located?

The registrar for the NS's domain, and then the registrar transfer 
the NS host data to the

Len : In Austin, TX; SFO, CA; Paris, 
FR : ISC BIND 8.2.3 "NT3" for NT4 & W2K  : Build free, hi-perf, anti-abuse mail gateways

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