Krishna said:
I have two DC's. Each is indiviual forests. Server A is meant for only
DNS/DHCP services. Server B is for logon, fileserver and other
applications.
Generally it is counter-productive to have two DCs but only
only one of them as a DNS server: DC replication and authentication
both require DNS so if the one with DNS is down clients will
either fail to replicate or experiencing slow logons at best.
Now, I have a XP box which obtains IP and DNS from Server A(st.abc.net)
but
cannot join Server B (efg.net). How to resolve?
Server B is in an different DOMAIN?
You are going to have to clarify this since when you write
2-DCs we presume you mean in a single domain where
both should be using the same DNS-domain-name suffix
(e.g, abc.net OR efg.net but not both.)
If you really do have two domains then each will need its
own DNS ZONE (not necessarily it's 'own' DNS server but
that is common practice.)
Each domain must have that DNS zone and it must be dynamic
to support AD.
If you have more than one domain, or even just multiple DNS
zones, there must be a way for each DNS server to find ALL
such zones to make everything work.
With multiple DNS servers sets (one set for each DNS zone
to support each domain) then you need to find a way to get
from each DNS server to the "other zone" -- usually with
Win2000 you will need each DNS server to hold a 'secondary'
for the "other zone".
--
DNS for AD
1) Dynamic for the zone supporting AD
2) All internal DNS clients NIC\IP properties must specify SOLELY
that internal, dynamic DNS server (set.)
3) DCs and even DNS servers are DNS clients too -- see #2
4) If you have more than one Domain, every DNS server must
be able to resolve ALL domains (either directly or indirectly)
netdiag /fix
....or maybe:
dcdiag /fix
(Win2003 can do this from Support tools):
nltest /dsregdns /server
C-ServerNameGoesHere
http://support.microsoft.com/kb/q260371/
Ensure that DNS zones/domains are fully replicated to all DNS
servers for that (internal) zone/domain.
Also useful may be running DCDiag on each DC, sending the
output to a text file, and searching for FAIL, ERROR, WARN.
Single Label domain zone names are a problem Google:
[ "SINGLE LABEL" domain names DNS 2000 | 2003 microsoft: ]