Networking 2 Buildings, each with their own ADSL connection

I have a network in our main office. We have a bldg further up the road from us. I currently have a 'leased' line between them (I work for the phone comp) - no problem, ppl from other bldg are on our office network, but they also use our internet connection. I want to setup their own internet connection so they don't steal our bandwidth. But I want them to be able to access our domain servers. How do I set this up? I want the other bldg to be able to log into the domain, but I want their internet traffic to go through their own conenction, not our office one. I also want the remote bldg to have DHCP so thet if someone plugs in a laptop, they'll have access to all the resources as well, without having to enter a static Ip address everytime. How do I setup DHCP to assign the remote bldg an IP, yet have their gateway point to their internet connection - but I don't want the office PC's to obtain an ip meant for the remote site since the gateway info will be wrong. ??? I've been playing with some routers and routing tables... is there an easier way (without having to set up a multi homed PC to do DHCP and routing) I want the easiest way!
Who is Participating?
I wear a lot of hats...


Chris StauntonCommented:
What types of routers do you have at each site?  Are there machines that are server class on their side of the pipe?  What do they use for an internet connection?  It's just a matter of route statements for you to point their internet traffic out their internet router and point the rest of their traffic over your leased line connection.  I'm hoping they have some kind of server class machine that can run a DHCP server on their end, otherwise you'd have to user dhcp helper commands in your router and somehow setup a scope for their IP pool.  I'm sure someone else might have an easy solution to this for you as well.


Simply put, assign the machines in building B with a gateway pointing to router B.
if you do not want them using your internet line, then you must purchase their own.  I would cancel the "leased" line if possible depending on contract terms.  Or see if they can change the line for no penalty to an internet line.  Then have a vpn device at each site.   you could purchase 2 pix 501's (1000 bucks total for 2) adn create static vpn tunnel between both sites.  the remote site would be able to hit anythign the host site (domain controllers, printers, etc) plus each site has their own internet line.  only LAN traffic would go over the tunnel.
Expert Spotlight: Joe Anderson (DatabaseMX)


guylajAuthor Commented:
Thanks for the comments...
We are the local telephone company, so the cost of the 'leased' line and the ADSL is not an issue... It all free for us :)

When I say a 'leased' line, we operate with Paradyne ADSL modems, and with these modems, we can set some dip switches on them to allow us to setup an ADSL modem at both ends of the phone line and both modems communicate with each other. The speeds of this connection aren't bad, but not the fastest. Good enough for logging into the domain and stuff, but we want the remote site to have their own ADSL modem for internet so that we decrease the traffic between sites and leave it for important things like logging into the domain or getting email from our exchange server etc...

I do understand routing tables, and I was playing around with them in one of my routers. Curt R, I have a Netgear router which does let me manually edit routing tables, so I guess that would work. I'm still left with the DHCP problem though. I've tried setting up a subnet at the remote location (main office 192.1.1.?, remote 192.1.2.?) which kinda worked, but I could not browse the network in network neighbourhood because it's a different subnet. I could live with this, not that big of a deal, but is there a better way of doing this? I want some suggestions on how to accomplish this since I can't really think of a way to do it and have everything work seamlessly - as if it was still setup as it is now, but with the remote location using their own ADSL Internet connection.

How are the buildings connected together?  are you using a bridge over the leased line or a router?  If you're simply bridging the networks, then simply assigning the computers in Building A with a gateway = router connected to dsl in building A and the computers in buildinb B with a gateway = router connected to dsl in building B should work for you, no?  This way, you have the leased line doing your network bridge between the buildings, and all traffic for your local subnet will travel through there, and all traffic destined for other networks will be routed through either router.

Or, if your only concern is one network hogging the bandwidth of your DSL connection, you could always install a router that supports load balancing multiple broadband connections, and connect two DSL lines to it.

Experts Exchange Solution brought to you by

Your issues matter to us.


Start your 7-day free trial
How are you making out with this?

From novice to tech pro — start learning today.