topic Re: host file in Operating System - HP-UX

host file

Sylvie Vezina — Thu, 04 Mar 2004 13:49:10 GMT

We run Unix 11.00 on L1000 server.
How to reload host file without server reboot.
We tried /usr/sbin/inetd -c: no result...
Can you tell me which command can we use?
Thanks

Re: host file

Sridhar Bhaskarla — Thu, 04 Mar 2004 13:52:46 GMT

Hi,

Can you give us more details?. If you are talking about /etc/hosts, then there is no need to restart everything. The new entry will be picked up by all the subsequent gethostbyname|addr calls. TO verify it use
'nslookup host_name' command.

Also make sure you have files appearing as the first option in your /etc/nsswtich.conf.

If you are not talking about /etc/hosts, then you can ignore this entire message.

-Sri

Re: host file

Marco Santerre — Thu, 04 Mar 2004 13:52:51 GMT

Bonjour Sylvie,

tu ne serais pas suppose d'avoir besoin de rebooter le serveur si tu ne fais qu'un changement a l'interieur de ton /etc/hosts. A partir du moment ou ton /etc/hosts est change, le changement est automatique.

Le probleme reside peut-etre de la maniere dont tu resous les adresses par contre. Comment est-ce que tu resous les adresses (regarde ton fichier /etc/nsswitch.conf) Si tu regardes files en premier, et que tu fais un ping sur le nom (ou l'adresse) que tu as change tu devrais resoudre a la nouvelle adresse.

Re: host file

Kent Ostby — Thu, 04 Mar 2004 13:55:05 GMT

If you are talking about the /etc/hosts file then there is nothing you need to do to make the system "re-read" it.

The problem may be that you have and /etc/resolv.conf file which is telling the computer to look at a different source rather then the /etc/hosts file.

Best regards,

Kent M. Ostby

Re: host file

Hazem Mahmoud_3 — Thu, 04 Mar 2004 13:57:20 GMT

Once the /etc/hosts file is updated, the changes take effect. Unless you are using DNS or NIS, and in that case the system may be going there first to resolve the host name. Take a look at your /etc/nsswitch.conf file and the /etc/resolv.conf files and let us know.

-Hazem

Re: host file

Geoff Wild — Thu, 04 Mar 2004 14:03:23 GMT

Yes - what is in /etc/nsswitch.conf?

Like:

hosts: files [NOTFOUND=CONTINUE] dns

Or: hosts: dns

If the latter - then it won't read /etc/hosts at all....

Rgds...Geoff

Re: host file

Sylvie Vezina — Thu, 04 Mar 2004 14:03:57 GMT

You were right, problem was DNS resolution....But many of you mentionned nsswitch.conf....and I don't find this file on system.....Must I create it or not?

Re: host file

Patrick Wallek — Thu, 04 Mar 2004 14:07:58 GMT

Yes, you should create it. It controls the order in which the hosts file and / or DNS/NIS/NIS+ etc will be checked for hostname resolution.

Mine generally look like this:

# ll /etc/nsswitch.conf
-rw-r--r-- 1 root sys 345 Jul 2 1998 /etc/nsswitch.conf

# cat /etc/nsswitch.conf
hosts: files[NOTFOUND=continue UNAVAIL=continue] dns [NOTFOUND=return UNAVAIL=continue TRYAGAIN=return]
protocols: files[NOTFOUND=return UNAVAIL=return]
services: files[NOTFOUND=return UNAVAIL=return]
networks: files[NOTFOUND=return UNAVAIL=return]
netgroup: files[NOTFOUND=return UNAVAIL=return]
rpc: files[NOTFOUND=return UNAVAIL=return]

The line you are most concerned about is the first line (the hosts: line). Mine checks the local /etc/hosts first and then looks to DNS.

Re: host file

Dave La Mar — Thu, 04 Mar 2004 14:16:22 GMT

Sylvie -
Marco did indeed point to nsswitch.conf.
No points here.
You should be all set with the given answers.

Best regards,

dl

Re: host file

Francois LAURENT — Fri, 05 Mar 2004 04:02:31 GMT

Hello,
Also use /etc/resolve.conf for indicate wich dns server to use :
domain XX.YYYY.fr
search XX.YYYY.fr
nameserver1 128.240.229.18
nameserver2 128.240.229.34

You can use nslookup and nsquery to verify the host resolution (#nsquery hosts hostname_to_resolve )

Re: host file

Mobeen_1 — Fri, 05 Mar 2004 05:40:43 GMT

Sylvie,
The order of name resolution is first any name call looks up the local hosts file and in the event that the host entry is not present in the local hosts file, then it will lookup your DNS server.

Your local hosts file will be at /etc/hosts

So if you would need to add in an entry for a host, you can just edit this file and add in that entry.

No reboot is needed after doing this, as after you are done editing the hosts file, any lookups to the host you added will be looked into the /etc/hosts file before going to your DNS server

I hope i have been clear

regards
Mobeen