Inconsistent name resolution & NDRs

[Kevin Darcy]

1. 202.54.105.2 doesn't appear to be answering queries, at least not from my
part of the Internet.

2. 202.54.102.19 is answering authoritatively for the zone, but it knows
nothing of the name "delns.ongc.co.in" so it therefore does not provide the
proper glue record in its responses, leaving only the address of the
unreachable (or partially-reachable) server for other nameservers to use. I
notice that a delns.delhi.ongc.co.in name exists in the zone, resolving to the
same 202.54.102.19 address. Did you perhaps change the DNS name of this
nameserver, without updating your NS record or delegation glue record?
Unfortunately, it appears that you have *two* A records defined for
delns.delhi.ongc.co.in, and one of them looks to be bogus (according to the
registries I checked, including APNIC, the 192.9.200/24 netblock is
unassigned). You really shouldn't be putting bogus addresses in the public DNS,
especially for nameservers. Those should be in the internal side of a
"split" DNS, if at all, and it would probably be best to use the RFC 1918
ranges for them.

3. There are a number of reasons why zone transfers can break. You could have a
bad IP address in the config file. Firewalls or routers between the servers may
need to be reconfigured to allow TCP DNS traffic. You may have a bad
"allow-transfer" ACL on the master. The "named-xfer" executable on the slave
may be corrupted, incompatible (e.g. from a different BIND version), in the
wrong directly, or otherwise unrunnable. If you're running as a non-root user,
maybe "named-xfer" can't write to the working directory. These are just a few
possible causes off the top of my head. You should look at your logs.


- Kevin

skt wrote:

> We have following situation
>
> our domain name is registered with local isp as ongc.co.in. As the
> organisation is geographically distributed, the administrator at central
> location created a subdomian bby.ongc.co.in for our location and mapped it
> to our NS. We are having SOA for bby.ongc.co.in subdomain. In order to
> receive e-mails we have made MX record and A record entries in our bby
> subdomain name server. We are facing following problems -
>
> 1) when we do nslookup at central primary name server, as expected , we get
> following response - (ddnns.ongc.co.in is our primary name server at central
> location)
>
>  QUOTE
> C:\>nslookup - ddnns.ongc.co.in
> Default Server:  ddnns.ongc.co.in
> Address:  202.54.105.2
> > set type=ns
> > bby.ongc.co.in
> Server:  ddnns.ongc.co.in
> Address:  202.54.105.2
> Non-authoritative answer:
> bby.ongc.co.in  nameserver = periyar.bby.ongc.co.in
> periyar.bby.ongc.co.in  internet address = 202.54.23.133
> > set tyupe=mx
> > bby.ongc.co.in
> Server:  ddnns.ongc.co.in
> Address:  202.54.105.2
> Non-authoritative answer:
> bby.ongc.co.in  MX preference = 10, mail exchanger = vbmail.bby.ongc.co.in
> bby.ongc.co.in  nameserver = periyar.bby.ongc.co.in
> vbmail.bby.ongc.co.in   internet address = 203.197.18.178
> periyar.bby.ongc.co.in  internet address = 202.54.23.133
>  UNQUOTE
>
> whereas if we do nslookup at our secondary name server delns.ongc.co.in we
> get following unexpected result -
>
>  QUOTE
> C:\>nslookup - delns.ongc.co.in
> Default Server:  delns.delhi.ongc.co.in
> Address:  202.54.102.19
> > set type=ns
> > bby.ongc.co.in
> Server:  delns.delhi.ongc.co.in
> Address:  202.54.102.19
>
> *** delns.delhi.ongc.co.in can't find bby.ongc.co.in: Non-existent domain
>  UNQUOTE
>
> What could be the reson for bby subdomain entries made about 3 months back
> not being replicated to our secondary name server till now ?Similar type of
> strange results are observed if we try to do nslookup at some other public
> ISPs name servers.At some locations we get results as expected whereas at
> other locations it says bby.ongc.co.in as non existent domain. Following are
> some screen shots from two different public ISPs name servers -
>
>  QUOTE
> ISP no. 1
>
> C:\>nslookup - mumbai.mtnl.net.in
> Default Server:  web1.mtnl.net.in
> Address:  203.94.227.73
> > set type=ns
> > ongc.co.in
> Server:  web1.mtnl.net.in
> Address:  203.94.227.73
> Non-authoritative answer:
> ongc.co.in      nameserver = delns.ongc.co.in
> ongc.co.in      nameserver = ddnns.ongc.co.in
>
> delns.ongc.co.in        internet address = 202.54.102.19
> ddnns.ongc.co.in        internet address = 202.54.105.2
> > bby.ongc.co.in
> Server:  web1.mtnl.net.in
> Address:  203.94.227.73
>
> *** web1.mtnl.net.in can't find bby.ongc.co.in: Non-existent domain
>  UNQUOTE
>
> ISP no. 2
>  QUOTE
> C:\>nslookup - 202.54.1.30
> Default Server:  dns.vsnl.net.in
> Address:  202.54.1.30
>
> > set type=ns
> > ongc.co.in
> Server:  dns.vsnl.net.in
> Address:  202.54.1.30
>
> Non-authoritative answer:
> ongc.co.in      nameserver = delns.ongc.co.in
> ongc.co.in      nameserver = ddnns.ongc.co.in
>
> delns.ongc.co.in        internet address = 202.54.102.19
> ddnns.ongc.co.in        internet address = 202.54.105.2
> > bby.ongc.co.in
> Server:  dns.vsnl.net.in
> Address:  202.54.1.30
>
> Non-authoritative answer:
> bby.ongc.co.in  nameserver = periyar.bby.ongc.co.in
>
> periyar.bby.ongc.co.in  internet address = 202.54.23.133
>  UNQUOTE
>
> The subdomain was created about 3 months back and records should have been
> streamlined by this time.
> what could be the reason of such un-expected behavior of name resolution ?
>
> 2) The second problem faced is that any mail sent from hotmail to users at
> <username>@bby.ongc.co.in gives following NDRs. whereas mails from other
> mail servers including yahoo mail etc. are being received without any
> problem.
>  QUOTE
> This is an automatically generated Delivery Status Notification.
>
> Delivery to the following recipients failed.
>
> sm.rasal at bby.ongc.co.in
>
> Reporting-MTA: dns;mail.hotmail.com
> Received-From-MTA: dns;mail.hotmail.com
> Arrival-Date: Wed, 13 Sep 2000 05:09:14 -0700
>
> Final-Recipient: rfc822;sm.rasal at bby.ongc.co.in
> Action: failed
> Status: 5.0.0
>
> ----------------------------------------------------------------------------
> ----
>
> From:  "subodh tewari" <subodh_tewari at hotmail.com>
> To:  sm.rasal at bby.ongc.co.in
> Subject:  test mail
> Date:  Wed, 13 Sep 2000 12:09:14 GMT
>
> _________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
> Share information about yourself, create your own public profile at
> http://profiles.msn.com.
>  UNQUOTE
>
> What could be the reason of these NDRs by hotmail server to mails addressed
> to bby.ongc.co.in? Why no such thing is happening from yahoo mail servers ?
> Our tech support says that hotmail has disabled recursive dns resolution
> features in its messaging servers for security reasons and any mails
> delivered to a subdomain within a FQDN will generate these type of NDRs.
> However It's not convincing to me.
>
> Please help
>
> skt