Mailing List SIMS@mail.stalker.com Message #13056
From: Bill Cole <listbill@scconsult.com>
Subject: Re: Mac.com errors
Date: Fri, 23 May 2003 09:17:32 -0400
To: SIMS Discussions <SIMS@mail.stalker.com>
At 1:12 PM -0500 5/22/03, Joe Sporleder  imposed structure on a stream of electrons, yielding:
How can I check this myself (I'm running MacOS X on this iBook, so am looking at the Network Utility that comes with MacOS X).

You can use that gadget if you like but it isn't quite as flexible as using the tools it uses, from a Terminal window.

In Network Utility, go to the Lookup tab and enter your address. Select 'Host name for address' from the pull-down menu, and uncheck the box to use dig. That will show whether you have reverse DNS for your machine, based on the default DNS settings on that machine. Note that this can be a little deceptive because if you happen to be sitting behind a resolver that talks to a machine that is supposed to be authoritative for the reverse DNS for that address, you will get an answer, even though the world at large may not know to talk to that machine (which is at least part of the Sprint problem.)

You can get a more flexible tool by opening a Terminal window and using dig directly:


dig -x  199.3.212.26

That will do a reverse lookup for your address and show you all of the response.  It should include one PTR record in the 'ANSWER SECTION' listing.

For me, that command yields this:

$ dig -x  199.3.212.26    ; <<>> DiG 8.3 <<>> -x
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 2
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUERY SECTION:
;;      26.212.3.199.in-addr.arpa, type = ANY, class = IN

;; AUTHORITY SECTION:
3.199.in-addr.arpa.     2H IN SOA       ns1-auth.sprintlink.net. dns-admin.sprintlink.net. (
                                        2003050501      ; serial
                                        3H              ; refresh
                                        1H              ; retry
                                        4W              ; expiry
                                        2H )            ; minimum


;; Total query time: 5500 msec
;; FROM: toaster.scconsult.com to SERVER: default -- 127.0.0.1
;; WHEN: Fri May 23 09:06:01 2003
;; MSG SIZE  sent: 43  rcvd: 112



That indicates that the nameserver running on my own machine only found the authority record for 3.199.in-addr.arpa (reverse DNS for 199.3.*) and nothing deeper. It is possible that my nameserver is acting up, so I can jump over it with dig and find the place where it seems this problem will be fixed, when it is fixed:

$ dig  @ns1-auth.sprintlink.net -x 199.3.212.26

; <<>> DiG 8.3 <<>> @ns1-auth.sprintlink.net -x
; (1 server found)
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 4
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUERY SECTION:
;;      26.212.3.199.in-addr.arpa, type = ANY, class = IN

;; AUTHORITY SECTION:
3.199.in-addr.arpa.     2H IN SOA       ns1-auth.sprintlink.net. dns-admin.sprintlink.net. (
                                        2003050501      ; serial
                                        3H              ; refresh
                                        1H              ; retry
                                        4W              ; expiry
                                        2H )            ; minimum


;; Total query time: 211 msec
;; FROM: toaster.scconsult.com to SERVER: ns1-auth.sprintlink.net 206.228.179.10
;; WHEN: Fri May 23 09:13:44 2003
;; MSG SIZE  sent: 43  rcvd: 112


That tells me that the nameserver at ns1-auth.sprintlink.net still knows nothing more about the reverse resolution of 199.3.212.26 beyond the facts that it is authoritative for reverse DNS under 199.3.* and there are no records currently for your address or for a delegation of authority for 199.3.212.*.


--
Bill Cole                                  bill@scconsult.com

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