Fablexo,
As Chriss was asking, did you set up your Subnets and associate them with
the correct Site in your Active Directory Sites and Services MMC?
This is the way to do this. You should create each Site first. Then, for
each Site you have you will have at least one subnet ( possibly more ).
Create each Subnet and - during the creation of each Subnet - associate that
Subnet with the correct Site. Let's look at an example:
You have four physical locations: New York, Miami, Los Angeles and Chicago.
Let's say that your company started in Los Angeles. You would have set up
the two DCs already and there is, by default, a Site created for you. No
problems there. You have your intrasite replication working just fine (
hopefully! The KCC usually does a really good job ) but do not have any
intersite replication yet.
Later you open up New York and Miami. You place two DCs in each city so
that you have the redundancy that is so very important. However, you do
need to create the Sites in the ADSS MMC. So, go ahead and create a new
Site for New York and a new Site for Miami. As I mentioned, you have the
intrasite replication working just fine ( again our friend the KCC takes
care of that just swell ) but need to have the intersite replication ( so
that New York knows what is going on with the DCs in both Los Angeles and
Miami and so that Miami knows what is going on with the DCs in both New York
and Los Angeles and blah! blah! blah! ). You would need to set up Site
Links. This is about the only thing - as far as AD replication is
concerned - that you *need* to do. And it is important that this be set up
correctly.
When you set up the Sites for New York and for Miami you would also need to
set up the appropriate Subnets. Let's just say that there are only some 50
users in both Cities. Your Los Angeles Site has a subnet of 192.168.10.x so
you decide that New York can use 192.168.20.x and that Miami can use
192.168.30.x. Set up the subnet 192.168.20.x and associate that with the
New York Site and then set up the subnet 192.168.30.x and associate that
with the Miami Site.
Simply make sure that your clients are receiving the correct IP Address
leases with the appropriate additional information ( typically Options 003,
006 and 015 ) and your issues should be resolved.
Now, Chicago comes into play. Go into the ADSS MMC and create the Chicago
Site. You decide to give Chicago a subnet of 192.168.40.x. Create that
Subnet and associate it with the Chicago Site. Make sure that your DHCP
Server ( whether a WIN2000 system or a Firewall or Router is supplying your
clients with the proper information ) and you should be good to go.
Please note that the intersite AD replication happens between the
'BridgeHead Server' in each Site. Typically, you do not need to select one
as one will be selected for you.
I would strongly suggest that you have some sort of Firewall-to-Firewall VPN
( aka Site-to-Site VPN ) between each Site.
You might also want to consider having a Global Catalog Server in each Site.
In case this was too much to digest, please take a look at the following
MSKB Articles:
How to Create and Configure a Site
http://support.microsoft.com/?id=318480
How to create a Site Link
http://support.microsoft.com/?id=316812
How to configure Site Link replication
http://support.microsoft.com/?id=321253
Description of BridgeHead Servers
http://support.microsoft.com/?id=271997
How to create a Global Catalog Server
http://support.microsoft.com/?id=313994
How to optimize the location of a DC or GC
http://support.microsoft.com/?id=306602
How a WIN2000 client locates a Domain Controller
http://support.microsoft.com/?id=247811
How a WINXP client locates a Domain Controller
http://support.microsoft.com/?id=314861
HTH,
Cary
PS - the last two links show you how the clients locate a DC. From these
two MSKBs you can see how important it is to have the Sites and Subnets set
up correctly. Also, even if you have this set up correctly there can be
issues. Please look at the 'How to optimize the location of a DC and GC'
for specific information on how to resolve this ( HINT: generic records ).
