In this demonstration, we'll configure our site topology for our environment.
Recall that we have in my timw.info forest I have a
root domain and a child domain.
I have two read/write domain controllers in the root.
In the child, I have a read/write and a read‑only domain controller.
Now, remember that I give you the topology diagram in the exercise files,
so don't forget about that, okay?
We again are on our windows 11 administrative workstation,
and we'll want to open up the Sites and Services console.
So I'm going to do a Run and do a dssite.msc to quickly shortcut that process.
Yes, I'm a nerd.
I love to touch type.
I type like 85 words a minute, so it's just faster for me
to type these more than anything else.
Okay, so again,
our goal here is to inform Active Directory of the physical
topology of our forest and of our domains.
So let's expand Sites,
and we can see that all of the domain controllers in the
forest go in Default‑First‑Site‑Name.
Now I'm going to pretend that my headquarters, my timw.info, is in Nashville.
So I'm going to actually reuse Default‑First‑Site‑Name and
I'm going to rename it Nashville‑HQ.
Now, I'm now going to right‑click Sites,
and we'll imagine that we have another site in Memphis.
I'm in Tennessee in theU.S., by the way.
And then we select a site link for this site.
The default IP site link, of course, is called DEFAULTIPSITELINK,
and I'll leave that alone.
It tells us here that we've created the site,
but to finish the configuration we need to ensure that Memphis is
linked to other sites with site links as appropriate.
We have to add subnets and then we have to install or move
domain controller objects over there,
so I want to make sure to do that sooner rather than later.
Let me lay out my subnets here.
Let me right‑click the Subnets, and go to New Subnet,
and I'm going to call this Nashville‑1.
And I'm going to call this in our Nashville headquarters we've got 10.1.0.0/24.
That's in Memphis‑HQ, as you can see.
So we're creating using CIDR notation an IPv4 and/or IPv6
designation, I'm using IPv4 here, and I'm going to add in the
subnets in the Nashville‑HQ location.
Let me do that one more time.
And I also have in Nashville, 10.2.0.0/24.
Let me link that up.
And then for the child domain in Memphis,
let me add the subnet or subnets there, there's two of them.
I'll call this one 10.3.0.0/24, this is Memphis.
And then lastly, I will do one more subnet, 10.4.0.0/24, also in Memphis.
Lastly, we want to make sure that our servers are placed appropriately.
Now in Nashville, rootdc1 and rootdc2 are there, so that's
fine, but I want to take my cdc1, that's my read/write
domain controller, and my CRODC1,
that's my read‑only domain controller, and associate them with
Memphis. You can't drag and drop, so let me right‑click and
select Move, and let me choose Memphis.
And then for CRODC1, right‑click, Move, select Memphis.
And so at this point, we've aligned our physical LAN
topology with Active Directory sites.
We've also arranged our domain controllers into those appropriate sites.
Lastly, we have our Inter‑Site, I said, lastly,
I guess I really mean it this time, we've got two different protocols to choose
from for your site links. There's Internet Protocol, or IP,
which is definitely the standard nowadays.
I mean, back in 2000, in the very early 2000s, you might have sites with
such limited network connectivity, dial‑up modem is what I'm thinking, to
where you could send replication updates using the Simple Mail Transfer
Protocol, or SMTP, but nowadays,
I mean, I don't know anybody in the industry that's using
SMTP, but it's still there as a possibility.
And so the DEFAULTIPSITELINK, notice that we look at the site link properties,
in this case I'm just going to leave the one. We're saying that Memphis and
Nashville have this site link between them, and we assign an arbitrary cost
value and then we can adjust the replication. Remember, 180 minutes is the
default inter‑site replication interval.
I know I have super high speed connectivity, so I'm going to
cut that down significantly. Now, the idea is that if you have
multiple site links between sites,
one may be preferred, so you can set it at a lower cost than the other manually.
Now notice that the KCC component that's running on your domain controllers
is always looking at latency itself, so it may choose another cost path
depending on what it sees in terms of reachability. Notice here we can
change the replication schedule again. This dialog is so old; it dates back
to Windows NT in the 1990s.
Notice that replication is allowed 24 hours a day by default, but
you can adjust and remove some of the coloration here to specify
intervals that are not available.
I mean, I can't think of a reason why you wouldn't want to
enable this around the clock nowadays, but 20‑something years ago,
during off business hours and if you're paying a lot for your bandwidth,
you may not want replication to take place, so this schedule is available.
If you right click within that Inter‑Site Transports,
you can create site links on your own.
You give it a name,
you specify the connectivity between the sites, and then as I mentioned
before, you adjust the cost and the replication interval.
This is a relatively simple environment here, so I think we're good to go
within the timw.info domain tree within this forest. As long as your
credentials support the operation, in other words,
you're an enterprise administrator,
we can work across our bidirectional forest trust to adjust our
site topology in acq, our trusted forest.
We can right‑click here, Change Forest, in this case acq.com.
Alright, then we can expand Sites. In this case, again, we have the
Default‑First‑Site‑Name and we have just the one domain controller.
But then the same procedure I just showed you applies here.
We could set up our subnets, and link our sites to those
subnets, and link our servers to our sites, and then
depending upon how many sites you have,
you may want to lay in some site links where you can adjust the cost and
replication interval. In terms of easily viewing replication metadata and
statistics, there's always, as I said earlier,
the repadmin command line tool.
So here we are at an elevated PowerShell prompt on my Windows 11 workstation.
I'm going to invoke Enter‑PSSession to do a PowerShell remoting
session to rootdc1 using my current credentials.
And once I'm there,
let me do a repadmin replsummary just to get some metadata back.
Though this is going to show replication frequency, fails, and it's
good that we don't see any failures or error messages here, that's
definitely what we want to see.
Let me clear the screen. We'll also do repadmin /showrepl, and then we'll
focus on rootdc1.timw.info, what are its replication partners, in other
words. Well, here we can see the different partitions,
the Schema partition,
the DomainDnsZones partition, and we can see the bridgehead
servers at each site and see when the last attempt to issue a
replication update happened and whether it was successful or not,
so it's showing us here per domain, per partition.
Let me clear the screen one more time, and if we do a
dcdiag /?, that'll give us a run of help.
Let me scroll up to the top. And let's just do a DnsForwarders test,
dcdiag /dnsforwarders to double‑check our forwarder. Again,
we have a number of built‑in tests. Dcdiag is essentially a diagnostic suite.
Let me scroll back up.
It's not necessary to really deep dive on the output, I just
want to just put a name to a face, so to speak.
Let's take a look, repl, let's take a look at some replication options.
How about we test connectivity, dcdiag
/test:connectivity, and it passed those tests.
So I'm seeing all green here, but as you can see, some of these tools
like repadmin and dcdiag, if you are experiencing latency update
issues with Active Directory replication,
your first line of defense would be to check out those tools.
And as you can see, they're very quickly done interactively
from a command prompt environment.
And then if you get errors back,
you can then take the next step in your troubleshooting. Let me do an exit here to quit my remote session, and there you have it.