How best to segment my LAN? 800 PC's 1 Subnet

Hi, I have 800 PC's and 1 subnet. I'm using Windows 2000/2003 servers and Windows 2000/XP Clients. I have no pre Windows 2000 clients. I run IP only in a fully switched LAN. I do have a layer 3 switch at the core but not at the workstation end. I run one Windows domain. I'm stuck as to the best way to move forward. Can anyone recommend an easy transition to reduce broadcasts

Will one Windows domain operate in two subnets
Will having a layer 3 switch at the core help me

Many thanks

"SW" <(E-Mail Removed)> ha scritto nel messaggio
news:CE8255DD-8EDD-42C4-9A0C-(E-Mail Removed)

> Will one Windows domain operate in two subnets?

Yes, if the routing between them and the AD sites are properly configured.
But remember to place (at least) a DC in each subnet.

Massimo

"SW" <(E-Mail Removed)> wrote in message
news:CE8255DD-8EDD-42C4-9A0C-(E-Mail Removed)...
> Hi, I have 800 PC's and 1 subnet. I'm using Windows 2000/2003 servers and
Windows 2000/XP Clients. I have no pre Windows 2000 clients. I run IP only
in a fully switched LAN. I do have a layer 3 switch at the core but not at
the workstation end. I run one Windows domain. I'm stuck as to the best way
to move forward. Can anyone recommend an easy transition to reduce
broadcasts?
>

Divide your current subnet into smaller subnets. How does your traffic
flow? Is there traffic between groups of machines, if so, put them in the
same subnet. If it's just workstations, talking to servers on separate
subnets, I'd aim for around 100 workstations per subnet. Layer three
switches in the core will make things pretty easy to configure as they are
basically routers.

> Will one Windows domain operate in two subnets?

A domain can operate in any number of subnets, as long as DNS and routing
are configured properly. If you are using DHCP and don't want DHCP servers
on each subnet, you will need to setup DHCP forwarding in your layer 3
switches.

> Will having a layer 3 switch at the core help me?

Yes, each switch port can be a separate subnet or multiple subnets with VLAN
tagging.
Your switch vendor should have example configurations supporting multiple
subnets.

There is no relationship between Windows Domains and LAN subnets. There is
no need to have a DC in each section unless those sections are across slow
WAN link. With normal LAN speed of 100mbps (or even the old 10mbps) keeping
the DCs in the same segment will be fine.


--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com


"Massimo" <(E-Mail Removed)> wrote in message
news:%23PX%(E-Mail Removed)...
> "SW" <(E-Mail Removed)> ha scritto nel messaggio
> news:CE8255DD-8EDD-42C4-9A0C-(E-Mail Removed)
>
> > Will one Windows domain operate in two subnets?
>
> Yes, if the routing between them and the AD sites are properly configured.
> But remember to place (at least) a DC in each subnet.
>
> Massimo
>

We split ours up using an HP 5300 series switch that has Layer3 routing. It
works perfectly fine. I grouped the workstations with the servers and
printers they use into the same subnets together. The more "general"
servers like DC's, DNS, WINS, DHCP I have just left them right where they
were in their original subnet.

The DHCP Servers (2) simply has a separate scope for each subnet with the
address pool split evenly between the two using the "exclusions" and the HP
Switch/Router is rigged to forward the DHCP Requests to the DHCP Servers.

The hardest part was just making sure that the subnets were properly split
up to get the effect I wanted. The next hardest was moving the patch cables
and readdressing the static equipment without causing a lot of disruption.

Since my original subnet had enough addresses to keep things going, I just
moved things in small chunks to the new subnets over a period of time.


--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com


"SW" <(E-Mail Removed)> wrote in message
news:CE8255DD-8EDD-42C4-9A0C-(E-Mail Removed)...
> Hi, I have 800 PC's and 1 subnet. I'm using Windows 2000/2003 servers and
Windows 2000/XP Clients. I have no pre Windows 2000 clients. I run IP only
in a fully switched LAN. I do have a layer 3 switch at the core but not at
the workstation end. I run one Windows domain. I'm stuck as to the best way
to move forward. Can anyone recommend an easy transition to reduce
broadcasts?
>
> Will one Windows domain operate in two subnets?
> Will having a layer 3 switch at the core help me?
>
> Many thanks

"Phillip Windell" <@.> ha scritto nel messaggio
news:%23%(E-Mail Removed)

> There is no relationship between Windows Domains and LAN subnets.

I know this... I never said there is one :-)

> There is
> no need to have a DC in each section unless those sections are across slow
> WAN link. With normal LAN speed of 100mbps (or even the old 10mbps)
> keeping the DCs in the same segment will be fine.

That's true, but in order to reduce traffic between subnets (which I suppose
is what the author of the original post wants) a DC would surely help.

Massimo

"Massimo" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> > There is no relationship between Windows Domains and LAN subnets.
>
> I know this... I never said there is one :-)

Ok, no prob..

> > no need to have a DC in each section unless those sections are across
slow
> > WAN link. With normal LAN speed of 100mbps (or even the old 10mbps)
> > keeping the DCs in the same segment will be fine.
>
> That's true, but in order to reduce traffic between subnets (which I
suppose
> is what the author of the original post wants) a DC would surely help.

Yea. There is some give and take there. The replication between the DCs can
end up causing some of the traffic that you try to eliminate. If there are
files to be replicated it can become kinda bad. It can become a balancing
act, but with normal LAN speeds it may work out the same either way,...the
slow WAN links are what can get you into trouble.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com

"Phillip Windell" <@.> ha scritto nel messaggio
news:OSk2%(E-Mail Removed)

>> in order to reduce traffic between subnets (which I
>> suppose is what the author of the original post wants) a DC would surely
>> help.
>
> Yea. There is some give and take there. The replication between the DCs
> can end up causing some of the traffic that you try to eliminate. If
> there are files to be replicated it can become kinda bad. It can become a
> balancing act, but with normal LAN speeds it may work out the same either
> way,...the slow WAN links are what can get you into trouble.

Of course; but in this case the subnets are quite full of clients (he's
going to use three or four of them, I think), and 200 PCs querying a domain
controller can generate much more traffic than an AD replication...

Massimo