Name resolution and mail problem
Brian Sommers
sommersb at nichols.com
Fri Oct 22 15:00:38 UTC 1999
I'm trying to debug mail delivery errors to a domain. The system that
cannot deliver is running BIND 8.2.2 and sendmail 8.9.3. I also have a
system running a BIND 4 (think it's 4.9.7) and sendmail 8.8.8 that has
no problem delivering the same message.
I want to think that the site has some DNS configuration problems and
that the BIND 8 is less forgiving than the BIND 4 counterpart. Below are
some of the checks I made.
The thing I thought might be an error is that the name servers listed
for whois are not given any NS records for the domain (or the SOA) when
I get a dump for the primary nameserver (see the last section).
-- [ here are the errors from sendmail that syslogd logged ] --
Oct 22 08:09:40 6C:mx1 sendmail[156362]: MAA127462:
to=<mguidry at usunwired.com>, delay=20:04:43,
xdelay=00:00:00, mailer=esmtp, relay=usunwired.com., stat=Deferred: Name
server: usunwired.com.: host name
lookup failure
Oct 22 08:19:05 6C:mx1 sendmail[163413]: HAA163588:
to=<mguidry at usunwired.com>, delay=00:44:46,
xdelay=00:00:15, mailer=esmtp, relay=usunwired.com., stat=Deferred: Name
server: usunwired.com.: host name
lookup failure
Oct 22 08:20:14 6C:mx1 sendmail[163413]: MAA127462:
to=<mguidry at usunwired.com>, delay=20:15:17,
xdelay=00:00:00, mailer=esmtp, relay=usunwired.com., stat=Deferred: Name
server: usunwired.com.: host name
lookup failure
-- [ I can resolve the domain name, FWIW ] --
nslookup usunwired.com
Server: mx1.nichols.com
Address: 0.0.0.0
Name: usunwired.com
Address: 207.191.51.5
-- [ dig finds the A record, but cannot get the MX records ] --
root(mx1): dig usunwired.com
; <<>> DiG 8.2 <<>> usunwired.com
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0
;; QUERY SECTION:
;; usunwired.com, type = A, class = IN
;; ANSWER SECTION:
usunwired.com. 23h59m34s IN A 207.191.51.5
;; AUTHORITY SECTION:
usunwired.com. 23h59m34s IN NS ns3.usunwired.net.
usunwired.com. 23h59m34s IN NS ns4.usunwired.net.
;; Total query time: 10 msec
;; FROM: mx1.nichols.com to SERVER: default -- 0.0.0.0
;; WHEN: Fri Oct 22 08:34:08 1999
;; MSG SIZE sent: 31 rcvd: 96
root(mx1): dig usunwired.com mx
; <<>> DiG 8.2 <<>> usunwired.com mx
;; res options: init recurs defnam dnsrch
;; res_nsend[signed] to server default -- 0.0.0.0: Connection timed out
-- [ same thing for host ] --
root(mx1): host usunwired.com
usunwired.com has address 207.191.51.5
root(mx1):
-- [ found their name servers ] --
root(mx1): whois usunwired.com
Registrant:
US-Unwired (USUNWIRED-DOM)
One Lakeshore Drive Ste 1900
Lake Charles, LA 70602
US
Domain Name: USUNWIRED.COM
Administrative Contact:
U.S. Unwired Admin (US69-ORG) admin at USUNWIRED.COM
(800) 673-2200
Fax- (318) 497-3442
Technical Contact, Zone Contact:
US Unwired Admin (UU7-ORG) domain at USUNWIRED.NET
(800) 673-2200
Fax- (318) 497-3442
Billing Contact:
U.S. Unwired Admin (US69-ORG) admin at USUNWIRED.COM
(800) 673-2200
Fax- (318) 497-3442
Record last updated on 11-May-1999.
Record created on 07-Nov-1997.
Database last updated on 21-Oct-1999 04:53:13 EDT.
Domain servers in listed order:
DNS1.USUNWIRED.NET 207.191.50.250
DNS2.USUNWIRED.NET 207.191.51.250
-- [ do an nslookup on the first server to look for MX and find two ] --
root(mx1): nslookup
Default Server: mx1.nichols.com
Address: 0.0.0.0
> server DNS1.USUNWIRED.NET
Default Server: DNS1.USUNWIRED.NET
Address: 207.191.50.250
> ls -t mx USUNWIRED.COM.
[DNS1.USUNWIRED.NET]
$ORIGIN usunwired.com.
@ 1D IN MX 20 backmail.usunwired.net.
1D IN MX 10 mail
> mail.USUNWIRED.COM.
Server: DNS1.USUNWIRED.NET
Address: 207.191.50.250
Name: mail.USUNWIRED.COM
Address: 207.191.51.246
> backmail.usunwired.net.
Server: DNS1.USUNWIRED.NET
Address: 207.191.50.250
Non-authoritative answer:
Name: backmail.usunwired.net
Address: 207.191.51.251
>
-- [ however I cannot get a regular nslookup to resolve their first MX
host ] --
root(mx1): nslookup mail.usunwired.com
Server: mx1.nichols.com
Address: 0.0.0.0
*** mx1.nichols.com can't find mail.usunwired.com: Non-existent
host/domain
root(mx1): nslookup backmail.usunwired.net
Server: mx1.nichols.com
Address: 0.0.0.0
Non-authoritative answer:
Name: backmail.usunwired.net
Address: 207.191.51.251
-- [ same thing for dig ] --
root(mx1): dig mail.usunwired.com
; <<>> DiG 8.2 <<>> mail.usunwired.com
;; res options: init recurs defnam dnsrch
;; res_nsend[signed] to server default -- 0.0.0.0: Connection timed out
root(mx1):
root(mx1): dig backmail.usunwired.net
; <<>> DiG 8.2 <<>> backmail.usunwired.net
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
;; QUERY SECTION:
;; backmail.usunwired.net, type = A, class = IN
;; ANSWER SECTION:
backmail.usunwired.net. 23h48m52s IN A 207.191.51.251
;; AUTHORITY SECTION:
USUNWIRED.NET. 1d23h29m7s IN NS DNS1.USUNWIRED.NET.
USUNWIRED.NET. 1d23h29m7s IN NS DNS2.USUNWIRED.NET.
;; ADDITIONAL SECTION:
DNS1.USUNWIRED.NET. 1d23h29m7s IN A 207.191.50.250
DNS2.USUNWIRED.NET. 1d23h29m7s IN A 207.191.51.250
;; Total query time: 12 msec
;; FROM: mx1.nichols.com to SERVER: default -- 0.0.0.0
;; WHEN: Fri Oct 22 09:04:30 1999
;; MSG SIZE sent: 40 rcvd: 139
-- [ now I dump all their records and see a possible problem with the NS
data ] --
root(mx1): nslookup
Default Server: mx1.nichols.com
Address: 0.0.0.0
> server DNS1.USUNWIRED.NET
Default Server: DNS1.USUNWIRED.NET
Address: 207.191.50.250
> ls -t any USUNWIRED.COM.
[DNS1.USUNWIRED.NET]
$ORIGIN usunwired.com.
@ 1D IN SOA ns1.usunwired.net.
admin.usunwired.net. (
1999102101 ; serial
1H ; refresh
30M ; retry
1W ; expiry
1D ) ; minimum
1D IN NS ns3.usunwired.net.
1D IN NS ns4.usunwired.net.
1D IN A 207.191.51.5
1D IN MX 20 backmail.usunwired.net.
1D IN MX 10 mail
newmail 1D IN A 207.191.3.73
localhost 1D IN A 127.0.0.1
mail 1D IN A 207.191.51.246
www 1D IN A 207.191.51.5
ftp 1D IN CNAME www
@ 1D IN SOA ns1.usunwired.net.
admin.usunwired.net. (
1999102101 ; serial
1H ; refresh
30M ; retry
1W ; expiry
1D ) ; minimum
-- [ They list SOA=ns1.usunwired.net and NS=ns3.usunwired.net,
NS=ns4.usunwired.net, but no NS records
for DNS1.USUNWIRED.NET or DNS2.USUNWIRED.NET (from whois) ] --
So my questions are - is this a malformed setup, and is this something
that BIND 4 allows but BIND 8 doesn't? Or perhaps it is sendmail that
is being more strict?
I don't mind getting in touch with their admin to go over any problems,
but I am not sure if the problem is theirs or not. That's why I am
looking for some guru help...
Thanks,
Brian
--
Brian Sommers
Nichols Research
sommersb at nichols.com
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