Topic: Changing DNS for DHCP Clients

[Allen]

I'm a little lost on this one...

I'm running my SME box as our main DHCP/WINS/SAMBA server. Works awesome.

Thing is...my clients are getting DNS names like PC-0075, PC-0076, etc. I tracked it to the DNS DB where I see all these hard-coded names to IP's. Is there a way to dynamically update this?

As far as I can tell...if I make a manual hostname entry using the SME console it updates the DNS db fine with the new name...but clients running DHCP will have the PC-xxxx name for their system.

How can I get it to dynamically update the DB with the client's pc name?

Example..

My pc is called "Allen"...I set it to DHCP...users should be able to ping me as allen.mydomain.com, due to WINS it does work as allen. But if I do a ping -a 192.x.x.x on my IP it returns with PC-xxxx.

That confusing enough??

~allen

[Allen]

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[Michiel]

I've been thinking about this too. DHCP 3 does allow clients to update the dns server via dhcp. Unfortunately SME is still running on DHCP 2 (cf RedHat 7.3).

RPM's are available from RedHat and I tried them on a RH 7.3 install without a problem. Obviously there are some security issues here, but I believe they are limited and the advantages outweight the disadvantages.

So my question really is: Has anyone tried to upgrade DHCP to version 3 on a SME 5.5 or 5.6? Or is there a good reason not to do this?

Michiel

[Graeme Fleming]

Hmm, the reverse DNS works fine on my 5.5 box.  Checked why and found that etc/e-smith/templates/var/named/named.localnetwork folder that provides the service.  Further checking based on file dates confirmed that the files in this folder only execute when a manual hostname is entered in the server manager; this process generates the /home/dns/var/named/named.localnetwork file that does the work.

On some networks I have set some PC's to a 'static' IP by adding them into the hostnames panel (with their MAC address) when I want them to always be given the same IP from the DHCP, this provides the added bonus of the correct name when the system is pinged and also knowing what specific machine is doing what when viewing the logs.

Adding the addresses in manually is impractical in many instances but does have extra benefits such as being used to track unauthorised access to a network.

Not an answer but possibly of some use.

[Walter Padgett]

Good Morning,

I'm interested in the MAC address point of this discussion. I'm trying to figure out a way to only hand out addresses to authorized MAC addresses. It's kind of like the MAC address would be the userid and password to obtain an IP address, without it one couldn't get one to gain network access.

I have also seen the naming issue of PC-00??? but didn't know exactly where to look to fix it. I've seen some postings and contribs about dynamic DNS but I haven't looked at them since my SME server is not the DHCP server.

For the next school year I'm thinking of setting up two SME servers for the express purpose of separating my email/web server from my firewall/gateway. At that time, I intend to make the email/web server my DHCP server providing addresses to the local network. The reason for the MAC address point is that I have wireless installed and I know you can do some security in the access points but I still like the idea of MAC addresses being the key to getting an IP address.

Enough rambling, a penny for your thoughts.

Wally

[Allen]

yeah..the dynamic dns updates and stuff would be nice (like it is in W2K) hmm..maybe i'll look into this some more and see if I can implement it.

~Allen

[Graeme Fleming]

Looking for a place to start ...

http://www2.themanualpage.org/dhcp-dns/index.php3

Readme file seems to indicate that Bind 8 can accept dynamic updates and a few perl scripts can handle the rest of the messing around.