Active Directory Site Links

PR. · 31 Mar 2011 at 15:45

Can anyone clarify a best practice for this as I'm a bit confused.

Before we switched to Windows 2008 R2 we had a hub/spoke system. This worked reasonably well but it took a long time for replication to get through and quite often the connectivity on the hub goes down preventing AD sync.

Now with Exchange 2010 it seems that it relies on ADs IP Inter-Site Transport link to efficiently route emails. I assume that means that emails going from spoke 1 to spoke 3 all have to pass through the hub?

We've also recently deployed DFS and I've seen a few users looking at the wrong DFS target again this seems to be costing issues on the site links?

We have 10 sites and I was just wondering how people had configured theirs?

Thanks

ecksmen · 31 Mar 2011 at 17:23

You should be able to directly replicate between all servers. You shouldn't need a centralised "hub" to be the master (in terms of network position, not FSMO).

How often do you have replication set to go? I believe the default is 15mins.

If you users are hitting the wrong DFS referal server, it would suggest that either the DFS server or the client IP is not in the correct site allocation. Remember that the site also needs to have the client subnets attached to it, to know to keep clients talking to local servers.

mr.bond · 31 Mar 2011 at 20:44

As simple as possible (I've 40 sites). Give ADS&S an accurate picture of your network and it will just work. You can replicate data as often as you like betwen the DC's, that's up to yourself.
If you need hub and spoke, have hub and spoke, it really depends on your network and how you want replication to flow. For site links though, AD will manage these for you very well, just give it the correct information.

PR. · 31 Mar 2011 at 23:48

I would guess it was originally setup when the company switched to AD with Win2000, when I checked it it was configured:

Site 1 to Site 2
Site 1 to Site 3
Site 1 to Site 4
Site 1 to Site 5
all the way up to Site 1 to Site 10

with replication every 4 hours.

Initially I changed it to use the default site link which is all the sites in to one link (replication every 15mins), that seemed to work ok, but then I (perhaps unrelated) had an issue with Exchange...

The VPN WAN we have is a mesh every site is connected to every other site, however if a line goes down the backup line only connects to site 1. The issue then appeared that Exchange 2010 couldn't route email through site 1 to deliver internal mail to the other sites. Doing a bit of reading suggested that this was because of there being no alternative site link for it to use.