How can I unite two LAN connections on one network?

"That pretty much depends on what is coming out of these two outlets:

So you have two independent legal
broadband accounts (can be two DSL, two
cable or one of each.)

There are two terms that might be
associated with using two independent
Internet connections.


Combining bandwidth.
Load balancing two connections.


Let's assume that you have two 3 Mbit/s
connections, each capable to download
at 300 KB/sec.

With combined bandwidth you should be
able to download one file at
600 KB/sec.

With load balancing one single file
will not exceed a download speed of
300 KB/sec. However you can download two
files at 300 KB/sec or 4 files at
150 KB/sec, etc.

Unfortunately combining bandwidth can
not be done without the ISP providing
such a specific service.

Computers are Not mind readers. If the
two connections are not synchronized
at the source, your computer would know
how to combine it to a coherent page.

Any if and but about it is just
Wishful thinking.

The price of such a service (if
available) is usually much more
expensive than upgrading your
connection from the basic service to a
faster business or corporate service.

If you do have two independent
services you can achieve koad
balancing by using a Dual WAN Router.

This type of cable/DSL routers have
two WAN connections for two broadband
modems, and they would mange the
Internet traffic to the LAN to be used
in the most efficient way.

The ZyXEL P-663H-51 is such a router.

Source"

You can get routers with dual WAN ports, and connect one of these to each connection, or you can get a machine of your own with three network ports, and setup something like pfsense or Untangle on it. I've used some of the dual (and even quad) WAN Drayteks before, but I'm afraid I don't have model numbers handy. A google search for "Dual WAN router" should fine plenty.