topic Re: Connection Problem in Operating System - HP-UX

Connection Problem

Smirjit Singh — Fri, 09 Feb 2001 13:48:58 GMT

Today I got a strange problem. We have a D class server with two lan card. External is 208 segment & internal is 172 segment. In our primary nameserver external Ip address is registerd. So when our internal user tries to ping that server then they get external ip address.

Today I configured DNS on that server. When I have changed resolv.conf & put primary & domain name server. Then from internal network when user's was trying for telnet or ftp . It got strucked for near about two minutes. But when I delete nameserver line from resolv.conf then they was able to connect very quickly. It was showing connected at port ... & stucked for near about 2 minuts.

Now my question why it is happening. Why telnet & ftp would depend on NAMED. Would anybody pls clear my doubt on this matter.

Sandip

Re: Connection Problem

RikTytgat — Fri, 09 Feb 2001 15:55:17 GMT

Hi,

Everything requiring translation from hostname to ip address uses DNS (and hence named), if activated. The routines actually doing the lookup is called the 'resolver'. Depending on some configuration files (nsswitch.conf), it tries to find an ip address from the hosts file or from DNS.

For that matter, even a ping uses DNS if the host is configured to use DNS.

Does this answer your question??

Bye,
Rik

Re: Connection Problem

Rita C Workman — Fri, 09 Feb 2001 18:37:21 GMT

Here's a thread that explains it too....

http://us-support.external.hp.com/cki/bin/doc.pl/sid=0ca6086d1a8af7533e/screen=ckiDisplayDocument?docId=200000027709160

/rcw

Re: Connection Problem

John Bolene — Fri, 09 Feb 2001 19:21:00 GMT

The user must have been connecting to the named machine which probably exists only in the hosts file on the server. Try putting the hosts file entry first in /etc/nsswitch.conf to resolve local entries before external entries.
The data in this file may look something like:
hosts: files [NOTFOUND=continue UNAVAIL=continue TRYAGAIN=continue] dns [NOTFOUND=return UNAVAIL=continue TRYAGAIN=return]

Re: Connection Problem

Smirjit Singh — Mon, 12 Feb 2001 04:41:16 GMT

Hi Rita,

Thanks a ton for that link.

Yes the problem was same as described in that link.

Sandip