Forum Moderators: open
If that can be done, Is there any way to configure dns to balance the requests out between the 5 addresses
Thanks
However I believe that what you want can be found by searching for [multi-homed server]. There are several "meanings" but one is "single NICs with multiple IP addresses are multihomed".
An interesting idea. If you do follow through perhaps you could post a "how to" thread for reference.
Sure, you CAN. But what are you trying to accomplish? I can't see any possible advantage to this, unless you are doing something very specialize that requires a very minimum of latency connecting to local machines, and you can't even stand the latency of a switch.
You can get reasonably-priced network cards with 2 or 4 connections. You can get more than that on one card for a pretty penny. Either Windows or Linux will configure easily for this out of the box.
What kinda computer do you have there that is going to out-run a Gig-E connection serving-up web pages? Colossus? Guardian?
As far as how, it depends on your OS. I use a homegrown linux, so I'm sure the way I do it is different than what you will need to do.
As for why, I have IP addresses from two different ISPs (I am running BGP for redundancy). Each IP block is on its own separate network. My web cluster frontend has a network card on each of these networks so I can serve pages on both IP blocks.
My machines with 3 or 4 cards are just used as gateways on internal subnets.
Failing that, I'd not be looking at multiple network cards (seems like that complicates matters quite a bit). Instead just assign all the IP's to one port, then connect that port to a router that has your web server on one connection, and your multiple internet connections plugged in there as well. That's almost exactly what I do and it's pretty easy to set up. In fact, assigning multiple IP's to one ethernet port is a whole bunch easier than assinging those same IP's to multiple ports, in linux at least (trust me, been down that road :) ).
As far as the DNS goes, you'll likely need a custom script that should probably go one better than randomly serving different IP's. Instead it should figure out where the request is coming from, and serve it the IP that has the closest route, if that can be figured out. Then you'll want to check if one of the providers is down and if so stop serving that IP.
Ugh. That's all rather ugly unless you're doing some very serious stuff. It's far easier, a ton less expensive, and probably far more robust to just get yourself colo'ed in a decent data center that has all this stuff done for you automatically.
server1 IN A 1.1.1.1
server2 IN A 2.2.2.2
www IN CNAME server1.domain.com.
IN CNAME server2.domain.com.
The DNS server will usually go into "round robin" mode with this configuration, and the client should use whichever is the first DNS record that is returned to it (since the DNS server will respond with all records for www)
