HELP! Caching DNS server wont resolve .EDU domains?
 

I need help with our caching DNS server. We are running RedHat Linux 6.1
with most of the updates as of a few months ago. A few days ago our DNS
stopped resolving, mostly to .EDU domains. Emails bounce, pings fail, etc.
Oddly, it seems to resolve internal domains as well as external .COM and
.GOV domains just fine! We havent changed a thing in our DNS, system, or
firewall setup recently. My best guess is that some kind of master DNS
list (named.ca?) for the up-level servers is corrupted. Any ideas what is
wrong and how I can fix it? I included some nslookup and dig output below.

Here is the output of a few nslookups (we are behind a NAT firewall, but the
ports are mapped from an external IP so dont let the 192.168 worry you).

> freehearts.com
Server: ns1.dqsoft.com
Address: 192.168.1.5

Name: freehearts.com
Address: 216.92.98.140

> dq.com
Server: ns1.dqsoft.com
Address: 192.168.1.5

Non-authoritative answer:
Name: dq.com
Address: 216.71.5.180

> yahoo.com
Server: ns1.dqsoft.com
Address: 192.168.1.5

Non-authoritative answer:
Name: yahoo.com
Addresses: 66.218.71.113, 66.218.71.112

> nist.gov
Server: ns1.dqsoft.com
Address: 192.168.1.5

Name: nist.gov
Address: 129.6.13.23

> ncar.edu
Server: ns1.dqsoft.com
Address: 192.168.1.5

*** ns1.dqsoft.com can't find ncar.edu: Non-existent host/domain

DIG OUTPUT:
<dqsoft.com> <118> % dig ncar.edu

; <<>> DiG 8.3 <<>> ncar.edu
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 4
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUERY SECTION:
;; ncar.edu, type = A, class = IN

;; AUTHORITY SECTION:
edu. 2h52m15s IN SOA A.ROOT-SERVERS.NET. NSTLD.VERISIGN-GRS.
COM. (
2002043000 ; serial
30M ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum


;; Total query time: 2 msec
;; FROM: dqsoft.com to SERVER: default -- 192.168.1.5
;; WHEN: Tue Apr 30 08:35:20 2002
;; MSG SIZE sent: 26 rcvd: 102

Blitzkrieg ('tanks in advance),
Christopher