Can I set up machine where the name lookup fails.

[prateek_1]

hi,

I need to make name lookup(hostname) fail and i can ping the machine in network only by it's IP address.

[Court Campbell]

don't add dns to the hosts line in /etc/nsswitch.conf.

[prasadb]

Also, comment the DNS server entries in /etc/resolv.conf

[OldSchool]

If OTHER machines are to access this server by IP only, then don't add entries for the server in question to your DNS server.

If you do, then the name will resolve on other machines that use the DNS database.

[prateek_1]

/etc/nsswitch.conf file is not present in /etc dir. here i can only see /etc/nsswitch.compat
file

[prasadb]

can you see /etc/resolv.conf file there..

give here

#cat /etc/resolv.conf

you must have entry of the DNS servers in this file , then comment the entries

[prateek_1]

I commented out each entry in /etc/resolv.conf file ,but i can still able to ping m\c by its hostname.

[Duncan Edmonstone]

You'll also need to comment out relevant entries in /etc/hosts file.

Duncan

[prateek_1]

I am allready comment out relevant entries in /etc/hosts file.but it still give hostname by hostname command actually i dont need it.

[Ivan Krastev · Accepted solution]

Are you pinging the server from other machine ? Change DNS record if yes.

regards,
ivan

[OldSchool]

as previously noted: if you do not want other machines to be able to access via hostname, you must not have entries for it in the DNS server(s).

if the are there, they need to be removed.

all of the stuff about resolve.conf and nssswitch only impact the local server's ability to resolve names. you seem to want to not access a specific server by a name (ip only). DNS is providing the name to other systems.

[Srimalik]

>I am allready comment out relevant entries in /etc/hosts file.but it still give hostname by hostname command actually i dont need it.

If host name command fails many softwares won't work.

If you want to disable DNS or hostname lookups :

delete /etc/nsswitch.conf
delete /etc/resolve.conf
remove entry for this host from /etc/hosts

After doing this u wont be able to resole any hostname. IP address will work though.

-Sri

[Ganesan R]

Hi Prateek,

It is not clear of what you need. "hostname" command is nothing to do with name resolution. It will just provide the name of that server.

If you don't want to ping/access any of the other servers by its name from one server, you should disable name resolution servies on that host. You can try the following.

If you have only "files" entry on nsswitch.conf, remove those entries from /etc/hosts.

If you have DNS or NIS entry on nsswitch entry, either you can disable those services or remove the entry from nsswitch.conf.

[prateek_1]

Thans All, issue got resolved.

[Torsten.]

Please consider to read this too:

http://forums13.itrc.hp.com/service/forums/helptips.do?#33

Have fun!

[Court Campbell]

It would have been easier to just copy /etc/nsswitch.compat to /etc/nsswitch.conf. I shouldn't have assumed you already did that.