question on setting up new subnet at branch office site

[gary]

we have two sites, main office and a few miles away we have a branch office.
have a T1 line going from main office site to our branch office. Cicso
routers on each end.

when we set things up a few years back we only have 15 PCs at the main
office, and 5 PCs at the other end of the T1.
so we had our one server at the main office, and everybody on the same
subnet.

Now its a few years later and our network has grown. we are going to be
adding 30-40 devices at the branch office, so I no longer will have enough
IP addresses on this one subnet.

We put another windows 2000 server at the branch office so they have their
own file server a few months back, so they have their own server.

what is the best way to put the branch office on their own subnet?

use the DHCP User Class Option on the main office server that currently is
the dhcp server? I understand you have to run a command on each device to
direct them to the correct subnet if we do that.

Or I could setup the branch office windows 2000 server as DHCP, but how
would I ensure that the PCs at the branch office would only grab IP
addresses from the server at the branch office?

set the branch office PCs gateway as the IP address of the branch office
2000 server?

 

[Kurt]

Without regard as to whether you are set up as an Active Directory domain:

If both ends are on the same subnet, then the T1 circuit is set up as a
bridge. I wouldn't go with client options in DHCP - it's just too much
administrative overhead. Re-configure the T1 as routed, and put the remote
site on it's own subnet. You can probably configure the Cisco router at the
branch office end to act as a DHCP relay. Then you can just create a scope
for the branch office on your existing DHCP server. The only problem with
this is that when the T1 is down, no DHCP leases will be handed out, and the
network (assuming the server has a static IP address as it should), won't be
functional. You could also probably configure the Cisco router to be a DHCP
server for the branch office.

If you have a Windows domain, you'll have lots of other things to consider.
With 30-40 new computers at the branch site, I'd consider having an on-site
domain controller.

....kurt

 

[gary]

well, actually we do have an onsite domain controller at the branch office.
a windows 2000 server used as a file server.

it is a windows 2000 active directory domain.
so what would I need to do to put them on a different subnet via the local
domain controller?

gary

 

[Guest]

Hi Gary,

A good solution is to setup 2 sites within Active Directory. One site for
the main office another for the branch. Each site would be on a different
network. You would do this from Administrative tools> Sites.

Main office could be 192.168.1.0/24
Branch office could be 192.168.2.0/24

The branch should have its own DHCP server. Since the DHCP server is in the
branch site, all workstations within that site when they send out a DHCP
request that server will respond. You would not have to worry about the
branch pcs getting ip addresses from the main office DHCP server because they
are within 2 different and distinct networks and within 2 different logical
sites. If you wanted the branch to obtain IP addresses from the main office
you would need to setup a DHCP relay agent.