DDNS with alternate IP configuration

I´m working on The Beast for the moment and i am using the MsPress book, wich is really great.

But i encounter one problem when doing the practice exercices:

I am using vmware 6.
This is the exercise setup:
- Physically networked two computers
- Assigned Computer1 a static address of 192.168.0.1/25
- Assigned Computer2 an alternate configuration address of 192.168.0.2/24

I installed DNS, promote Computer1 to DC.

Now my problem is Computer2 dont create dynamically A and PTR records in DNS with this alternate config, also tried to reboot computer2,start-stop dhcp client service,ipconfig /registerdns.

When i set a static address to Computer2, it registers normally, it creates A and PTR records.

Did someone else encounters this problem?

Find more posts tagged with

Save $250 on 2025 certification boot camps from Infosec!

Book now with code EOY2025

Button

Comments

sprkymrk

The alternate configuration address only comes into play when you have set "Obtain an IP address automatically" for the General TCP/IP properties, and it cannot contact a DHCP server. It will then use the alternate configuration, but will also continue to try and contact a DHCP server every 5 minutes. It won't be used at all if you hard code an IP address for the main TCP/IP properties.

Statically configured (non-DHCP) clients register both the A and PTR RRs with the DNS server themselves. Otherwise, I believe there has to be an address event (new address or renewal) for the client to register with the DNS server. I don't think this happens with the alternate configuration address.

I am still trying to find out more about this, but meanwhile I suppose you have already made sure that the " Register this connection’s address in DNS" checkbox is selected in Advanced TCP/IP properties on the client.

Interesting question....

GeorgeMcFly22

sprkymrk wrote:

I suppose you have already made sure that the " Register this connection’s address in DNS" checkbox is selected in Advanced TCP/IP properties on the client.

You know, for this practice exercices, i read the exercise once and then try to do it without following the book.

So i thought maybe i forgot to do something (like the "register this connection", or allowing dynamic updates).

So i reinstalled 2 virtual machines and this time did all the exercices step by step, to be sure i forgot nothing, but i came out to the same point.

I´m half past the mspress book now and suppose they need this alternate config, to use as dhcp client afterwards.

So, or i do like in the book and must manually create A and PTR records, or i set a static address, i know its not a big deal, but found it confusing and interesting at the same time.

sprkymrk

I agree. I was going to try setting an alternate ip on a laptop, then run a tcpdump while doing an ipconfig /registerdns but I got distracted and didn't complete the experiment. If I find something conclusive I'll post back.