nanog mailing list archives

Re: .gov registrar problem


From: Mark Andrews <marka () isc org>
Date: Fri, 24 Dec 2010 10:39:46 +1100


In message <AANLkTinr979Bw_Cr8DCL-hvhdGdN4V_zpFx9Dc=cU7Lt () mail gmail com>, Andy
 Harrison writes:
In case anyone else notices spotty problems resolving .gov names, I
just sent the following message to registrar () dotgov gov:

----

I started investigating a dns issue after we received a few customer
complaints regarding intermittent problems resolving hostnames under
noaa.gov.  After some in-depth investigation, I believe I've
identified the issue.

First, the query to see the list of authoritative name servers for .gov:

        # dig NS gov @c.root-servers.net

        ; <<>> DiG 9.6.1-P3 <<>> NS gov @c.root-servers.net
        ;; global options: +cmd
        ;; Got answer:
        ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53495
        ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 7, ADDITIONAL: 7
        ;; WARNING: recursion requested but not available

        ;; QUESTION SECTION:
        ;gov.                    IN      NS

        ;; AUTHORITY SECTION:
        gov.                    17280 0  IN      NS      f.usadotgov.net.
        gov.                    17280 0  IN      NS      a.usadotgov.net.
        gov.                    17280 0  IN      NS      g.usadotgov.net.
        gov.                    17280 0  IN      NS      b.usadotgov.net.
        gov.                    17280 0  IN      NS      d.usadotgov.net.
        gov.                    17280 0  IN      NS      e.usadotgov.net.
        gov.                    17280 0  IN      NS      c.usadotgov.net.

        ;; ADDITIONAL SECTION:
        a.usadotgov.net.        172800  IN      A 74.208.172.129
        b.usadotgov.net.        172800  IN      A 206.204.217.151
        c.usadotgov.net.        172800  IN      A 69.72.142.35
        d.usadotgov.net.        172800  IN      A 204.168.112.71
        e.usadotgov.net.        172800  IN      A 213.165.80.240
        f.usadotgov.net.        172800  IN      A 66.207.175.172
        g.usadotgov.net.        172800  IN      A 64.62.200.134

        ;; Query time: 9 msec
        ;; SERVER: 192.33.4.12#53(192.33.4.12)
        ;; WHEN: Thu Dec 23 17:37:59 2010
        ;; MSG SIZE  rcvd: 258

The glue records show a.usadotgov.net with an ip of 74.208.172.129.

Next, using one of the authoritative name servers for usadotgov.net,
we resolve the a.usadotgov.net name:

        # dig a.usadotgov.net @DNSSEC7.DATAMTN.COM

        ; <<>> DiG 9.6.1-P3 <<>> a.usadotgov.net @DNSSEC7.DATAMTN.COM
        ;; global options: +cmd
        ;; Got answer:
        ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61276
        ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 6, ADDITIONAL:  1
0
        ;; WARNING: recursion requested but not available

        ;; QUESTION SECTION:
        ;a.usadotgov.net.               IN  A

        ;; ANSWER SECTION:
        a.usadotgov.net.        86400   IN      A       76.73.18.236

You can see that the ip address is incorrect for that hostname.  This
is going to cause an issue where some responses for .gov addresses
will come from a non-authoritative source and should be taken care of
as soon as possible as this could potentially affect all .gov domains.

No, 76.73.18.236 is authoritative for gov as is 74.208.172.129.  It would
appear that a.usadotgov.net is being moved / re-hosted.  Discrepencies
such as this are normal when this is happening.

; <<>> DiG 9.6.0-APPLE-P2 <<>> soa gov +norec @76.73.18.236
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1312
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 7, ADDITIONAL: 0

;; QUESTION SECTION:
;gov.                           IN      SOA

;; ANSWER SECTION:
gov.                    259200  IN      SOA     A.USADOTGOV.NET. support.datamtn.com. 1293146225 3600 900 1814400 86400

;; AUTHORITY SECTION:
gov.                    259200  IN      NS      F.USADOTGOV.NET.
gov.                    259200  IN      NS      E.USADOTGOV.NET.
gov.                    259200  IN      NS      A.USADOTGOV.NET.
gov.                    259200  IN      NS      D.USADOTGOV.NET.
gov.                    259200  IN      NS      G.USADOTGOV.NET.
gov.                    259200  IN      NS      B.USADOTGOV.NET.
gov.                    259200  IN      NS      C.USADOTGOV.NET.

;; Query time: 231 msec
;; SERVER: 76.73.18.236#53(76.73.18.236)
;; WHEN: Fri Dec 24 10:38:24 2010
;; MSG SIZE  rcvd: 201

Mark

--
Andy Harrison
Lead Systems Engineer
Metrocast Cablevision

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka () isc org


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