Remote Name lookup problems

[Ken Causey]

I work with an ISP that has been receiving reports that users of other
ISPs cannot get to websites they host.  In an attempt to try to diagnose

the problem I've gotten access to another ISP's primary dns server
to do some testing and I am getting some very weird responses that
I would really like some help translating.

>From the other ISP's DNS:

[root at ns1 ken]# nslookup -d2 www.wbko.com.
;; res_mkquery(0, 11.70.77.216.in-addr.arpa, 1, 12)
------------
SendRequest(), len 43
    HEADER:
        opcode = QUERY, id = 39233, rcode = NOERROR
        header flags:  query, want recursion
        questions = 1,  answers = 0,  authority records = 0,  additional
= 0

    QUESTIONS:
        11.70.77.216.in-addr.arpa, type = PTR, class = IN

------------
------------
Got answer (201 bytes):
    HEADER:
        opcode = QUERY, id = 39233, rcode = NOERROR
        header flags:  response, auth. answer, want recursion, recursion
avail.
        questions = 1,  answers = 1,  authority records = 3,  additional
= 3

    QUESTIONS:
        11.70.77.216.in-addr.arpa, type = PTR, class = IN
    ANSWERS:
    ->  11.70.77.216.in-addr.arpa
        type = PTR, class = IN, dlen = 16
        name = ns1.muhlon.com
        ttl = 86400 (1 day)
    AUTHORITY RECORDS:
    ->  70.77.216.IN-ADDR.ARPA
        type = NS, class = IN, dlen = 2
        nameserver = ns1.muhlon.com
        ttl = 86400 (1 day)
    ->  70.77.216.IN-ADDR.ARPA
        type = NS, class = IN, dlen = 16
        nameserver = access.vci.net
        ttl = 86400 (1 day)
    ->  70.77.216.IN-ADDR.ARPA
        type = NS, class = IN, dlen = 6
        nameserver = ns2.muhlon.com
        ttl = 86400 (1 day)
    ADDITIONAL RECORDS:
    ->  ns1.muhlon.com
        type = A, class = IN, dlen = 4
        internet address = 216.77.70.11
        ttl = 86400 (1 day)
    ->  access.vci.net
        type = A, class = IN, dlen = 4
        internet address = 207.162.160.11
        ttl = 164540 (1 day 21 hours 42 mins 20 secs)
    ->  ns2.muhlon.com
        type = A, class = IN, dlen = 4
        internet address = 216.77.70.12
        ttl = 86400 (1 day)

------------
Server:  ns1.muhlon.com
Address:  216.77.70.11

;; res_mkquery(0, www.wbko.com, 1, 1)
------------
SendRequest(), len 30
    HEADER:
        opcode = QUERY, id = 39234, rcode = NOERROR
        header flags:  query, want recursion
        questions = 1,  answers = 0,  authority records = 0,  additional
= 0

    QUESTIONS:
        www.wbko.com, type = A, class = IN

------------
------------
Got answer (30 bytes):
    HEADER:
        opcode = QUERY, id = 39234, rcode = SERVFAIL
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 0,  authority records = 0,  additional
= 0

    QUESTIONS:
        www.wbko.com, type = A, class = IN

------------
*** ns1.muhlon.com can't find www.wbko.com.: Server failed


If this is done from the hosting ISPs internal network everything
works just fine.  What does an rcode of SERVFAIL mean?  And
I should mention that this seems to happen for many if not all
of the ISPs hosted domains.

Any help is greatly appreciated.

Ken Causey