strange reverse response

[Chris Buxton]

There's a lame referral from 40.140.217.in-addr.arpa to itself  
(coming from the bt.net servers). The +trace option to dig is pretty  
stupid with regard to referrals, so it just keeps on keepin' on in  
this case. Real name servers recognize that as an invalid response  
and refuse to continue.

There are three obvious solutions to this:

- BT could talk to RIPE and get some larger netblock reverse zone,  
such as 140.217.in-addr.arpa, delegated to them. This assumes that BT  
has such a netblock, which is what their server actually claims if  
you ask it.

- BT could talk to RIPE and get the /24 reverse zone delegated  
directly to you, without any stop on the way at BT.

- BT could slave your reverse zone, so that the four bt.net servers  
listed by RIPE are authoritative for your reverse zone.

Chris Buxton
Men & Mice
Take control of your network

On Sep 20, 2006, at 3:11 PM, Rodney J Mertz wrote:

> OK can someone help explain what is wrong here. A reverse search  
> without the
> +trace option fails:
> -------------------------
> # dig -x 217.140.40.10
>
> ; <<>> DiG 9.2.4 <<>> -x 217.140.40.10
> ;; global options:  printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 58147
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
> ----------------------------
> But if you add +trace it works properly!
>
>
> # dig -x 217.140.40.10 +trace
>
> ; <<>> DiG 9.2.4 <<>> -x 217.140.40.10 +trace
> ;; global options:  printcmd
> ..                       64752   IN      NS      e.root-servers.net.
> ..                       64752   IN      NS      f.root-servers.net.
> ..                       64752   IN      NS      g.root-servers.net.
> ..                       64752   IN      NS      h.root-servers.net.
> ..                       64752   IN      NS      i.root-servers.net.
> ..                       64752   IN      NS      j.root-servers.net.
> ..                       64752   IN      NS      k.root-servers.net.
> ..                       64752   IN      NS      l.root-servers.net.
> ..                       64752   IN      NS      m.root-servers.net.
> ..                       64752   IN      NS      a.root-servers.net.
> ..                       64752   IN      NS      b.root-servers.net.
> ..                       64752   IN      NS      c.root-servers.net.
> ..                       64752   IN      NS      d.root-servers.net.
> ;; Received 292 bytes from 127.0.0.1#53(127.0.0.1) in 0 ms
>
> 217.in-addr.arpa.       86400   IN      NS      SEC1.APNIC.NET.
> 217.in-addr.arpa.       86400   IN      NS      SEC3.APNIC.NET.
> 217.in-addr.arpa.       86400   IN      NS      SUNIC.SUNET.SE.
> 217.in-addr.arpa.       86400   IN      NS      NS-EXT.ISC.ORG.
> 217.in-addr.arpa.       86400   IN      NS      NS-PRI.RIPE.NET.
> 217.in-addr.arpa.       86400   IN      NS      TINNIE.ARIN.NET.
> 217.in-addr.arpa.       86400   IN      NS      NS3.NIC.FR.
> ;; Received 223 bytes from 192.203.230.10#53(e.root-servers.net) in  
> 73 ms
>
> 40.140.217.in-addr.arpa. 172800 IN      NS      ns0.bt.net.
> 40.140.217.in-addr.arpa. 172800 IN      NS      ns1.bt.net.
> 40.140.217.in-addr.arpa. 172800 IN      NS      ns2.bt.net.
> ;; Received 104 bytes from 202.12.29.59#53(SEC1.APNIC.NET) in 219 ms
>
> 40.140.217.in-addr.arpa. 300    IN      NS      ns2.syntegra.com.
> 40.140.217.in-addr.arpa. 300    IN      NS      ns3.syntegra.com.
> 40.140.217.in-addr.arpa. 300    IN      NS      ns4.syntegra.com.
> 40.140.217.in-addr.arpa. 300    IN      NS      ns1.syntegra.com.
> ;; Received 128 bytes from 217.35.209.188#53(ns0.bt.net) in 114 ms
>
> 10.40.140.217.in-addr.arpa. 21600 IN    PTR      
> relay11.mms.eu.btsyntegra.com.
> 40.140.217.in-addr.arpa. 21600  IN      NS      ns3.syntegra.com.
> 40.140.217.in-addr.arpa. 21600  IN      NS      ns4.syntegra.com.
> 40.140.217.in-addr.arpa. 21600  IN      NS      ns1.syntegra.com.
> 40.140.217.in-addr.arpa. 21600  IN      NS      ns2.syntegra.com.
> ;; Received 232 bytes from 150.143.80.2#53(ns2.syntegra.com) in 204 ms
>
>
>
>