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2 internet connections (seperate ISP's) one windows 2003 box with 3 nic's

I have a windows 2003 box with 3 nic's in it, one nic for the local network and two for two seperate ISP's  how would i configure the two wan connections so that traffic from one wan does not go out on the wrong interface? or how can I balance the load ?
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jasonslan
Asked:
jasonslan
2 Solutions
 
Rob WilliamsCommented:
You cannot do load balancing over 2 Internet connections with a standard Windows server. It is possible, with a few applications, to direct the traffic from that application to a specific interface using routing commands, but as a rule to do load balancing you will need a router designed for that purpose. There are many dual WAN port routers available, but one of the most affordable units, that offers many additional features is the Linksys RV042. It has two WAN ports that can be configured for 2 ISP's and will give you both fail-over protection if one connection fails, and load balancing over the 2 connections (about $200 US):
http://www.linksys.com/servlet/Satellite?c=L_Product_C2&childpagename=US%2FLayout&cid=1123638171618&pagename=Linksys%2FCommon%2FVisitorWrapper
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jasonslanAuthor Commented:
Actually. . . .
Network Load Balancing is included in all versions of Windows Server 2003
http://support.microsoft.com/kb/820752/?sd=RMVP&fr=1

I'm just not sure how to configure it.  and thats what i'm really wanting to use.

any tips on how to translate those instructions to meet my circumstances would be awesome.

--Jason
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Rob WilliamsCommented:
Never fails if I say you can't do something, I will be proven wrong.  :-)  
However, as far as I am aware, Windows Network Load balancing is only available to balance the "network load" over a cluster (group of servers).
http://www.microsoft.com/windowsserver2003/technologies/clustering/default.mspx
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/clustering/nlbfaq.mspx#EDB
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Sam PanwarSr. Server AdministratorCommented:
Hi,

Network Load Balance (NLB) component provided in Windows 2003, load balances incoming TCP and UDP traffic in to the 2 nodes it was configured.  So in it cannot load balance outgoing traffic.
So you can't use the window load balancing for it.

I think that what you're looking for would have to be handled by the router,similar to the reference link below:

http://lartc.org/howto/lartc.rpdb.multiple-links.html

I also suggest this darren mackey suggestion please see:

Realistically, to have both connections active, you need an ip address range that is routable through both providers, then get youy provider to advertise the address range (realistically need a class C for this though as most upstream providers will filter out advertised subnets smaller than
/24). then you load balance on metric (but windows does not load balance equal cost paths though... you would need a router, linux or bsd box). It would look like:

LAN---FW---Router---ISPA
             |
            ISPB

and the subnet between the firewall and the router would then need to be advertised by both ISPA and ISPB, or you could get a medium range router (such as cisco 3600s) or high and fill it with enough memory to handle BGP - most DLS providers do not allow this though...

There are however several options available to you that would spread some load to each ISP.

1. Set a single default route to ISPA, and then use the caching proxy of ISPB for browser traffic.

2. Place you DSL connections on a separate box capable of policy routing - apart form the fact it is a really bad idea to terminate you internet connection on a server!

- policy routing allows you to selectivey route based on protocol. For instance, you could have mail routed through ISPA with a high cost route through ISPB (when the route to ISPA is not available) and have say web traffic routed through ISPB and have a higher cost route for web traffic
through ISPA, etc, etc.
- Note that this is not load balancing, but spreading the load intelligently - and then have routes cut over when a link is down.
- I assume you are using NAT of some sort, os it is important to realise that using such a mechod will actually kill existing sessions when a link fails - as the internet is not a garranteed delivery mechanism this is OK.
- like so:

LAN---Gateway---ISPA
         |
        ISPB

Note that for mail, you need MX records pointing to the IP addresses for both of your DSL connections, otherwise when your 'mail' link fails, mail will cease to flow inbound (outbound will still deliver though..)!

As I said previously, the gateway requires policy routing capabilities. This could be cisco kit or a linux box (2.4 kernel) or bsd box. I gather more recent nortel routers (v14) would also have policy routing capabilities. Doing this with a single router could be quite expensive and you require 2 broadband interfaces, and I am not away that the ethernet wics are available for the 2600 series routers yet... (they will be supported in the future though)..

note - I have only shown schematics. It is assumed that you have / will have a firewall somewhere between the internet connections and you LAN!
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pjtemplinCommented:
"I want to use NLB to use two ISPs" is a wonderful statement, but that's just not what NLB is all about.
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carl_legereCommented:
If EE allowe the little people like us to create new TA's then Rob or I surely would have made the:
"I'm very excited to get two internet connections on my network, what do I do now?" TA by now.

I vote that you cannot use network load balancing to combine internet connections.

Why is your windows computer directly connected to either connection?
-Windows server makes a very expensive router.

clever routing can be used to separate for example EMAIL in and out from WEB traffic, thus load balancing the connections somewhat, but only on a per application basis.

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Rob WilliamsCommented:
Hi Carl, does seem like we meet on this question quite a bit.  :-)
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jasonslanAuthor Commented:
looks like I'm going to sell the two BEFVP41's that I currently have and purchase an RV042, seem strange that an entrylevel router can do this, but a brain and routing and remote access can not.. *shrug* I'm going to split the points between RobWill and Abs_jaipur  - thanks for all of your input.

--Jason
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Rob WilliamsCommented:
Thanks Jason, good luck,
--Rob

ps- There are 3rd party add-ons that will do it with 3 NIC's and a Linux box, but you have to be quite ambitious.
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jasonslanAuthor Commented:
I don't mind learning, as knowledge is power... but you're right the RVO42 is much easier and quicker (why re-invent the wheel right?) :-)
Thanks again Rob.

--Jason
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Rob WilliamsCommented:
Agreed, I don't have the patience to go down that road, that's a good high school project in my opinion. <G> Challenging an worth while, but I don't have the time.
Cheers,
--Rob
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