DHCP and Dynamic DNS Update for HP-UX 11.0

[adam carroll_1]

Greetings all:

I am trying to get dynamic DNS updating to work on my HP-UX 11.0 machine. I've got DHCP working fine, but I cannot seem to figure out any way to implement dynamic DNS update.

I saw one thread on forums.itrc.hp.com discussing this, but it ended in a usage error which I have recreated :) Can anybody comment further on how to make this happen in HP-UX 11.0?

Any help is appreciated -

AC

[A. Clay Stephenson]

If you are willing to do a little work (basically run make) and have a development environment (either gcc or better ANSI/C or aCC) then the very best source for this is www.isc.org. These are THE guys for DHCP and DNS (bind). It's a rather easy build and the dhcpd is very advanced; the dynamic DNS works very well. Bear in mind that Dynamic DNS is still a draft standard so ....

[Rainer von Bongartz]

Adam,

I have got it running so please post your /etc/dhcptab to see what you configured.
Also post your errors you refer to.

One thing is not working currently.

Supporting multiple subnets and moving your DHCP client through this subnets will fail to correectly update the DNS server.

A site specific patch from HP is promised to me for the next week, so I guess it will be released officially in a couple of weeks.

Regards
Rainer

[adam carroll_1]

Thanks for the replies. I think I may have not been clear enough in my original posting. I am not running DHCP server on my HP box, it is a DHCP client. I want the my HP box to do these steps:

o Get its networking config from a DHCP server on the network.

o Register itself with a DNS on the network.

Currently, the first step is working fine. I am getting the server on the network and all of the net configs are OK.

I have not managed to get the second part going, though. The usage error I mentioned is also mentioned in this thread:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xffb079bffde7d4118fef0090279cd0f9,00.html

Here is an excerpt:

thank you for the try.
It did not work:

htr02# dhcpclient -N htr02 -b lan0

usage:
./dhcpclient -b interface [-f tracefile] [-l debug_level] [-n][-p] [-t log_type] [-x send_attempts] [-z time_to_wait]
./dhcpclient -d interface
./dhcpclient -m interface [-f tracefile] [-l debug_level] [-p] [-t log_type] [-z time_to_wait]
./dhcpclient -r interface [-f tracefile] [-l debug_level] [-p] [-t log_type]
./dhcpclient -v


I've read about a utility for HP-UX 11i that does this - that is why I asked if 11.0 supports this functionality.

Any help is appreciated -

AC

[Bill Thorsteinson]

The Dynamic DNS with DHCP configurations I have seen
don't work as you are porposing. They work as follows:

Client Server:
- Gets configuration from DHCP.
- Updates resolve with nameservers from DHCP.

DHCP Server:
- Sends configuration to client.
- Updates DNS with client servers data.

DHCP can be configured to provide a static address for
specific servers (MAC addresses).

Dynamic DHCP requires that the DNS server be configured to
allow updates from the server performing the updates. The
above configuration is much
more secure than allowing any
computer on the DHCP subnet to
update the DNS tables.

If you have multiple names for the server, then arrange to have the additional names be CNAMES for the name registered
via DHCP

[adam carroll_1]

That makes sense - I actually thought that was the usual way it all worked until a colleague told me differently yesterday :)

Assuming it works that way, then, I have other non HP-UX servers (AIX, W2K) that are not having a problem with this. They are getting their network configs assigned properly and are being registered with a DNS. Once again, this is why I am suspecting there is something I am missing on my HP server, which is the DHCP client.

Are there any troubleshooting tips to pass along? Should I try to force a DHCP lease renewal? Are there any things I can check on the DHCP server (stale A,R records, etc.).

Thanks again,
AC

[Bill Thorsteinson]

On your client system:

- Check in /etc/rc.config.d/netconf that
DCHP_ENABLE is set to 1 for
the interface(s) that should
be using DHCP. Also check
that the IP is NOT statically
assigned.

- Verify that the DCHP client software is installed and
running. Check the /sbin/init.d directory for
a file that looks at DHCP_ENABLE. See which
program it runs and verify
that it is running:
ps -ef | grep -i dhcp

- Check the logs for dhcp messages.

- Restart the dhcp client using the /sbin/init.d script.
On HP you likely need to stop then restart the service.

On the DHCP server:

- find the file that records active leases. It should have
an active lease for the clients ip address. You can
also look for the mac addresss.

I hope this helps.