topic Re: How to clear the DNS cache in Operating System - HP-UX

How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 04:06:12 GMT

We have several HPUX server 11.i and 11.0
And we have an DNS server.
We are doing some tests and we would like
to know if a command or methode exists to
clear the DNS cache on our servers.

Thanks

Re: How to clear the DNS cache

Joel Girot — Tue, 12 Sep 2006 04:26:53 GMT

Hi Franck

rndc flush

see man rndc

Joel

Re: How to clear the DNS cache

spex — Tue, 12 Sep 2006 06:51:55 GMT

Hi Frank,

See Geoff Wild's response in this thread:
http://forums1.itrc.hp.com/service/forums/bizsupport/questionanswer.do?threadId=993552

PCS

Re: How to clear the DNS cache

Steven E. Protter — Tue, 12 Sep 2006 07:25:04 GMT

Shalom,

Indirectly changing the serial number on the zone record should trigger an immediate flush for that zone on all clients.

2006051301 becomes 2006091201 (today's date change 1).

Then restart bind.

Editing the zone records may be rough on named 4.9.7, I hope you are using Bind 8 or 9.

SEP

Re: How to clear the DNS cache

Geoff Wild — Tue, 12 Sep 2006 07:27:39 GMT

rndc flush

or stop/restart bind

Rgds...Geoff

Re: How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 07:51:38 GMT

When I try to man mdc it doesn't work or
exist ?
Where can I find the executable ?

[root@orasrv1:]/picnew/export/tp/backup/tp<>>> man mdc
No manual entry for mdc.
[root@orasrv1:]/picnew/export/tp/backup/tp<>>

Re: How to clear the DNS cache

Joel Girot — Tue, 12 Sep 2006 07:58:37 GMT

not mdc but RNDC in lowercase : rndc
man 1 rndc

Joel

Re: How to clear the DNS cache

spex — Tue, 12 Sep 2006 07:58:47 GMT

Hi Frank,

/usr/sbin/rndc

R N D C

PCS

Re: How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 08:03:04 GMT

Is that standard on 11.i ?
I do not have it on any of my machines,
which include a couple of 11.00 also.

[vwbsrv1:/root]# ls -altr /usr/sbin/mdc
/usr/sbin/mdc not found
[vwbsrv1:/root]#

Where can I download this or get this ?

Re: How to clear the DNS cache

Joel Girot — Tue, 12 Sep 2006 08:10:33 GMT

it is standard on 11i Franck but it is not mdc (MDC) but rndc (RNDC : r n d c)
$ ls -altr /usr/sbin/rndc
lrwxr-xr-x 1 root sys 31 Jan 18 2005 /usr/sbin/rndc -> /usr/contrib/bind/usr/sbin/rndc
Joel

Re: How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 08:16:44 GMT

Sorry about that, I am not paying attention to well.

In any case I tried the rdnc too
[vwbsrv1:/root]# ls -altr /usr/sbin/rndc
/usr/sbin/rndc not found
[vwbsrv1:/root]# ls -altr /usr/contrib/bind/usr/sbin/rndc
/usr/contrib/bind/usr/sbin/rndc not found
[vwbsrv1:/root]#

Still no joy.

I wonder why we do not have it.
Did I miss something during the installation years ago ??

Re: How to clear the DNS cache

Joel Girot — Tue, 12 Sep 2006 08:24:19 GMT

In my hpux 11.11 box rndc come with bind (v920)
# swlist -l product | grep -i bind
BINDv920 B.11.11.01.006 BIND 9.2.0 special release upgrade
PHKL_32038 1.0 Psets Enablement, Kernel Binding
PHNE_30068 1.0 Bind 8.1.2 Patch

Re: How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 08:27:55 GMT

Well thanks;
I seem to have nada

[vwbsrv1:/root]# swlist -l product | grep -i bind
[vwbsrv1:/root]# uname -a
HP-UX vwbsrv1 B.11.11 U 9000/871 2001097676 unlimited-user license
[vwbsrv1:/root]#

Re: How to clear the DNS cache

Geoff Wild — Tue, 12 Sep 2006 08:30:37 GMT

RNDC only comes with recent versions of Bind.

Depending on the versions you have installed, you may or may not have it...

What version of bind is running?

You can use dig (if installed):

dig @yourserver version.bind chaos txt

Or with nslookup:

nslookup -q=txt -class=CHAOS version.bind. yourserver

You could also just run a find command...

Rgds...Geoff

Re: How to clear the DNS cache

Joel Girot — Tue, 12 Sep 2006 08:47:10 GMT

on client side I don't think that it have dns cache. Only on server side. No need to flush on client side. Possibly see your /etc/hosts file.

Re: How to clear the DNS cache

spex — Tue, 12 Sep 2006 09:13:14 GMT

Hi Frank,

For older verions of BIND,

# /sbin/init.d/named stop
# /sbin/init.d/named start

will flush the cache.

PCS

Re: How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 09:18:38 GMT

Mr Spex

Is /sbin/init.d/named supposed to be running
on each client, or is this only
necessary on the DNS server ??

Re: How to clear the DNS cache

Joel Girot — Tue, 12 Sep 2006 09:20:45 GMT

Only on dns server Frank.

Re: How to clear the DNS cache

Frank de Vries — Tue, 12 Sep 2006 09:41:32 GMT

All your answers make me understand
where I stand.

The problem is that here we have dns not
on hpux (I wish it was) but on Windows (yeak).

thanks