Combining bandwidth...
 

Trying to help a friend with something:

Got this far; server 2003 with 4 nics.

I have 15 IP's at work. I want to give each WAN nic its own ip and thus, 5 MB of bandwidth. I want to combine the nics together to have a 15mb pipe then use RAS to NAT the LAN. What's the next step here? Load balancing? Multihoming? Bridging?

I'm going from RR Modem to switch to 3 WAN Nics and then LAN nic to main switch.

Anyone have any ideas, or if this is even possible? I know roadrunner here gives out a cap of 5mb download per IP (not modem / user).

Well, assign each NIC an IP address. What it sounds like you're looking for is something called Port Bonding. I have done this before with Linux, but not in Windows.

But geez, 15 public IP's and you're using a cable modem? Haha, that's funny.

Transmit Load Balancing (TLB) and Switch-Assisted Load Balancing (FEC/GEC/802.3ad static-mode configuration only) are two port-bonding methods. TLB provides both failover and balancing of transmit traffic across all adapters for increased performance. For even higher performance, Switch-Assisted Load Balancing (SLB) provides port failover and balancing of transmit and receive traffic across all adapters when connected to a switch that supports this feature.

bonding on a windows machine used to be very tricky. I'm not sure how it is today... but it was a real pain in the ass in Win2k

What you'll want to do is talk to Roadrunner and explain that you need the fifteen IP addresses (or however many) and that you want a business connection - it sounds to me like you purchased several residential lines (hence the 5Mbit cap) and are trying to bond them, but if you purchase a business line, you should be able to get much better speeds without the limits.

Port bonding really shouldn't be considered unless you absolutely cannot change the network setup because - as Cynthetiq said - it's a huge pain in the ass.

I would be telling my friend to get a better connection. Were I that friend, I would not be pulling you in to try port bonding on my business connection. Wars have begun over smaller things.

He might want to consider a load balancing switch and two broadband connections. Plug & go.

Roadrunner here starts out very cheap and gives you 15 IPs for business class. The more bandwidth you want, the price jumps up pretty quickly.

Plus, this is more of an experiment to see if it can be done than anything else.

Can you purchase two of the low-end lines for a reasonable price? With dual-WAN routers you can aggregate the bandwidth with a couple minutes of configuration. No Windows changes. I've seen (but not used) versions that support up to four connections. Cheap dual-WAN versions start below $100. Might be worth considering.