> and will look at the SOA of the domain they belong to??
They'll only need that if they're updating DNS directly, not via DHCP.
They'll need to be able to resolve host names and service records for the "other" domain via the DNS servers they use. If a trust is in place that kind of name resolution is already likely to be functional.
You can test that:
nslookup -q=srv _gc._tcp.domain.com
Should give you a list of Global Catalog servers for domain.com.
You're not really missing anything other than testing to make sure. It's quite a simple system really :)
> How do I get points without buying them? If I am an expert and the
> points I gain from answering, Can I use that to ask myself?
If you gain expert status you get unlimited points with which you can ask questions. Expert points are used for little more than ranking / status / self-satisfaction.
To earn expert status you will need to earn a total of 10000 points, and 3000 points a month to maintain that. Check the Help pages under Answering Questions for more details.
Chris