Using two broadband lines for redundancy?

[kyleawesome]

Hey guys, I havent been around for a little while (not too much mac talk going on here ;-) ) but I have come back with a question!

I have a few websites I host (just personal crap, portfolio, blog, you know) through a web host at about 20 bucks a month. I am interested in just making myself a server and hosting them myself. Then a buddy of mine came to me and say "hey, if you do get a server up and running, let me know, I could use some cheap hosting for my bands site." So I thought, I know a ton of guys that would love to have a webhost for like 3 bucks a month. Then I had a scary thought:

My host guarantee's 99.9% uptime, I am currently using comcast and well, they dont guarantee crap, but I do also have the option of getting free DSL from my apartments (768/256 not the fastest I know, but it would only be used for emergency's). They are private DSL lines, and I thought hmm if I can why dont I just use the comcast connection AND the DSL connection for redundancy?

I have looked around and I know you can shotgun 56k modems, but I havent seen too much in my situation. I wouldnt NEED both connections active all the time, while I would love to use my apartments DSL as a way to take any strain off of my Comcast connection. So my question is

how would I go about using both connections? I understand I would need to pick up two NIC's that can accept this type of set up, but besides that I dont really know what I would need.
Also what do you think? 6,768kbp/s down and 1,256kbp/s up, that would work out just fine for a smaller web server eh?

As always thanks in advance!!!

 

[Hawkeye22]

You need a router that supports 2 WAN links and has the ability for automatic fail over. These can get costly.

Even if you had one, it probably won't work (not the way you want). Your basic broadband cable and DSL providers usually block incoming traffic to ports 80 (HTTP) and 25 (SMTP), so you'd have to run your web server on a non-standard port. i.e. http://www.my-site.com:8080 instead of http://www.my-site.com.