特に問題なさげですね。

%dig +norec -t a a.b.c.d.e.f.bbm.2ch.net @b.ns.bbm.2ch.net

; <<>> DiG 9.3.1 <<>> +norec -t a a.b.c.d.e.f.bbm.2ch.net @b.ns.bbm.2ch.net
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 15677
;; flags: qr aa; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;a.b.c.d.e.f.bbm.2ch.net. IN A

;; AUTHORITY SECTION:
bbm.2ch.net. 2560 IN SOA a.ns.bbm.2ch.net. 2ch.2ch.net. 1121185800 16384 2048 1048576 0

;; Query time: 0 msec
;; SERVER: 206.223.151.221#53(206.223.151.221)
;; WHEN: Fri Jul 22 06:02:41 2005
;; MSG SIZE rcvd: 86