nslookup using localhost.0.0.0.127.in-addr.arpa as a nameserver

[Kevin Darcy]

The name shown for the nameserver ultimately doesn't matter much as long
as the queries are going to the right address. Apparently the address of
whatever nameserver your resolver is using reverse-maps back to the name
"0.0.0.127.in-addr.arpa". If you want that to map back to something more
reasonable, then you need to set up the appropriate reverse zone files. It
is not strictly necessary to be delegated the reverse domain, as long as
all of the servers which need to answer for the reverse zone(s) internally
are explicitly configured with it. If you have a *lot* of internal
servers, which would make explicit configuration difficult to maintain, or
wish to provide this reverse-zone information to the Internet, then you
would need to be delegated the reverse domain.


- Kevin

Hi
I recently set up my DNS servers. my domain is registered. But nslookup
deafults to using 0.0.0.127.in-addr.arpa as the default name server. I
have two static IP's and using them for my primary & secondary name
servers. the lookups of internal and external hosts works fine with
0.0.0.127.in-addr.arpa. But I am wondering why its not using my
primary server(say xxx.domain.com). Does reverse lookup needs to be in
place before name server is operational. I can provide with more
information.
The reverse lookup is is not delegated. Will this cause any problems?
Also outside name servers are not able to lookup my domain.
Any help is appreciated.
Thanks
Sent via Deja.com http://www.deja.com/
Before you buy.

[Joseph S D Yao]

I think I need to make myself more clear on this. Sorry if I was not
clear last time. I am new to DNS and excuse any blunders here.
I have two static IP address from my ISP
24.13.68.211 and
24.180.74.165
and I have nothing more. I don't think my ISP even supports DNS and
they will not.(which may mean that the reverse lookup is not going to
work)
I am trying to run a web server and wants to run my own DNS servers.
registered my domain which is learnfreeonline.com with internic
with
24.13.68.211 ---> ash.learnfreeonline.com primary DNS server
24.180.74.165 --> ash2.learnfreeonline.com as the secondary name server.
I configured DNS on 24.13.68.211.(I have not yet put DNS on
24.180.74.165).
when use nslookup from 24.13.68.211 (according to one of the books I
read about DNS , if the DNS server is set up correctly then
when I do nsllokup it should use ash.learnfreeonline.com as the default
server)
the server defaults to localhost.0.0.0127.in-addr.arpa as the server.
abc.com).
But when I tried to query my domain from my another naime server(from
myISP) using nslookup, the resolve failed.
i.e on my ISP nameserver nslookup learnfreeonline fails. I guess this
means that access to www.leranfreeonline.com from outside world will
fail.
1. why is the nslookup from 24.13.68.211 not using
ash.leranfreeonline.com as the dault server.
2. why is my ISP nameserver not able to resolve learnfreeonline.com
I can provide my db files and config file if required.
thanks
In article <39D11A8A.AC331CD at daimlerchrysler.com>,

Post by Kevin Darcy
The name shown for the nameserver ultimately doesn't matter much as

long

Post by Kevin Darcy
as the queries are going to the right address. Apparently the address

of

Post by Kevin Darcy
whatever nameserver your resolver is using reverse-maps back to the

name

Post by Kevin Darcy
"0.0.0.127.in-addr.arpa". If you want that to map back to something

more

Post by Kevin Darcy
reasonable, then you need to set up the appropriate reverse zone

files. It

Post by Kevin Darcy
is not strictly necessary to be delegated the reverse domain, as long

as

Post by Kevin Darcy
all of the servers which need to answer for the reverse zone(s)

internally

Post by Kevin Darcy
are explicitly configured with it. If you have a *lot* of internal
servers, which would make explicit configuration difficult to

maintain, or

Post by Kevin Darcy
wish to provide this reverse-zone information to the Internet, then

you

Post by Kevin Darcy
would need to be delegated the reverse domain.
- Kevin

Hi
I recently set up my DNS servers. my domain is registered. But

nslookup

Post by Kevin Darcy

deafults to using 0.0.0.127.in-addr.arpa as the default name

server. I

Post by Kevin Darcy

have two static IP's and using them for my primary & secondary name
servers. the lookups of internal and external hosts works fine with
0.0.0.127.in-addr.arpa. But I am wondering why its not using my
primary server(say xxx.domain.com). Does reverse lookup needs to be

in

Post by Kevin Darcy

place before name server is operational. I can provide with more
information.
The reverse lookup is is not delegated. Will this cause any

problems?

Post by Kevin Darcy

Also outside name servers are not able to lookup my domain.

First, some background.

The address "127.0.0.1" refers to your local host. That is, whatever
server you're on.

You should have your DNS set up so that when you look up "localhost"
from your domain [whatever that domain might be], it returns 127.0.0.1.

You should have your DNS set up so that when you try to do a reverse
DNS lookup on "127.0.0.1", it returns either "localhost." or
"localhost" followed by a your domain name. Another way of talking
about the same lookup is to say that you are looking up a PTR record
for "1.0.0.127.in-addr.arpa." Depending on how you are mistyping the
subject line of this message, you either have "localhost" [no dot] or
"localhost.0" on the right-hand side [RHS] of the PTR record in your
0.0.127.in-addr.arpa zone file. You should have "localhost." [with the
dot] on the RHS of that record.

And, as the Bard would have said were he ansering this message, a rose
by any other name still serves names. Does it really matter whether
'nslookup' calls your machine localhost, localhost.learnfreeonline.com,
or ash.learnfreeonline.com? It is ALL THE SAME MACHINE.

ANSWER TO 1.: It is. It is just using a different name.

You control resolution via /etc/resolv.conf. [This is a separate
process from serving names, which is controlled by /etc/named.conf.]
If you are really anxious to have ash in there, put its IP address in
there as a nameserver.

ANSWER TO 2.:
Systems such as your ISP's name server only know what they have been
configured to know, plus what they are told by other name servers. The
".com" name server had to have told them who your domain's name servers
are, before they could know.

I don't know what they showed before. Now they show:

learnfreeonline.com nameserver = ASH.learnfreeonline.com
learnfreeonline.com nameserver = ASH2.learnfreeonline.com

Authoritative answers can be found from:
learnfreeonline.com nameserver = ASH.learnfreeonline.com
learnfreeonline.com nameserver = ASH2.learnfreeonline.com
ASH.learnfreeonline.com internet address = 24.13.68.211
ASH2.learnfreeonline.com internet address = 24.180.74.165

HOWEVER:

*** No address information is available for "www.learnfreeonline.com"

Check your 'syslog' output for errors when loading this domain.

If you are behind a firewall, you will need to open a hole for this
domain. This is a very bad idea. It would be better if you had an
internal name server and an external name server, and a proxy at the
firewall. You do appear to be behind a firewall: a 'traceroute' shows:

...
10 cr1.avnl1.nj.home.net (24.3.128.62) 11.940 ms 12.611 ms 11.720 ms
11 cc325178-b.avnl1.nj.home.com (24.180.74.165) 117.119 ms * 91.268 ms
12 * * *
13 * * *
14 * * *
15 * * *
...

Or is @Home just continuing to be a bad netizen by blocking any queries
going in to a subscriber's site?