Network Load Balancing

Hi,

I got a problematic of network load balancing and I dont seem to find the
tools to do what I wand on windows.

Here is the situation, I got 2 network cards on my machine, connected on
different subnet with different default gateway and I want the machine to do
load balancing on those 2 interfaces. Actually I want the output traffic to
be sent equally over those 2 interfaces.

Im looking for a real load balancing solutions, not some workaround by
splitting routing tables for exemple ...

If you got suggestions ...

Thx.

Julien.

 

Hi,
think over your situation.

if a client on subnet A requests data, the machine answers to that subnet A
/ to that client ( and i guess you want this).
if the requested data were to the different subnet B, they would have a
value (for the client - especially if there is no further routing) like they
have been send to mars.

you may have a research on "trunking".

regards jk

 

Well lets simplifiy. Imagine I got 2 network cards on my windows server and
each one of those cards is connected to a different ISP. I just want the
output traffic of the server ( an internet gateway for my LAN for exemple )
to be load balanced equally between those 2 connections ... hope its clearer
now.

Thx for your answer by the way.

 

Won't happen.
This has to be done at a router.

If these are commercial lines (like T1s, D3, etc) this has to be a "real"
router and will be done with routing protocols. It will involve the router
at the ISP side and therefore requires that both lines come from the same
IP. Typically the ISP performs this for you.

If these are home user lines (DSL, CableTV) then this must be done with a
broadband "router" that has two WAN ports and is designed for this purpose.

Network Load Balancing in the Windows "context" is balancing "servers" as
in clustering, mirroring, whatever term your want to use and has nothing to
do with Lines and "connections".


--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.

 

Hi,

Thx for your answers but actually im not sure we're clear about what I want
to do. I dont want to load-balanced the input traffic, which I could have
done with the solutions you suggested : DNS round robin ...
What I want is to load-balanced the output traffic. If you want an exemple
look at this howto for linux system :

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

The only thing is that I want to do the same thing on a windows server ...

Thx again.

Julien.

 

I didn't suggest DNS round robin,...and I wasn't speaking of inbound
traffic. DNS round robin does not load balance at the outbound IP
connection level or at the outbound packet level,...like what I was
suggesting will do.

Commercial Lines done as I described will balance both directions

Home user lines done as I described will load balance only internally
initiated outbound traffic.

It is the way I said.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

 

Hi,

Sorry, I answered too quickly and I mut have msitaken your answer with
another one somebody made me on another forum. Whatever.

So to be clear for you there's absolutely no way to loadbalanced Home user
lines directly from windows server ? I got to use specific network equipement
to do that ?

That seems strange as long as that problematic seems quite common , but i
cant find anything on the web about such a solution so I begin to believe you
actually ...

Thx .

 

Windows can do "Dead Gateway Detection" which is a very "crude" form of
Fail-Over (not load balancing)

128978 - Dead Gateway Detection in TCP/IP for Windows NT
http://support.microsoft.com/default.aspx?scid=kb;EN-US;128978

171564 - TCP/IP Dead Gateway Detection Algorithm Updated for Windows NT
http://support.microsoft.com/default.aspx?scid=kb;EN-US;171564

It has been that way for years (about 10 years actually). So it is old news
to those of us that have been with Windows for a long time. The generic
TCP/IP Protocol, by itself, alone, just is not capable of such things.
Therefore it has to be over come with "software" at a higher lever in the
OSI model,..perhaps ever completely above the OSI model (hard to pin down
exactly where it all has to happen at). But anyway, Windows as an OS just
doesn't do it.

In routers,..that is "real" routers,...not home-user/consumer boxes that are
falsely called routers,...this would be done with Dynamic Routing Protocols
(like IGRP). Dynamic Routing Protocols are idealy suited to do this and it
is more or less what they do naturally anyway.

When "home user" line technologies were invented, meaning DSL and CableTV
Internet, they introduced new methodologies into how lines work. These
"home-user" boxes,...and even now some of the middle-range devices (like the
$400-$500 boxes from Cisco, Sonicwall, Watchgaurd) have the ability to do
this wilt two lines that are not even from the same ISP. IT is done with
some proprietary or semi-proprietary methods that do not involve Dynamic
Routing Protocols. Some companies may even be producing high-end Firewall
appliances that do this as well.

However because the two lines are seen on the Internet by two different IP#s
it only works outbound as far as I know. But the commercial lines (like
T1s) this can be done in both directions because the Destination via both
"paths" is identified by the same IP# and the Dynamic Routing Protocols make
it all happen.


--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

 

What about that ? :

http://www.geekswhoknow.com/articles/load-balance-two-internet-connections.htm

 

Oh and by the way, you were talking about "software" at a higher lever in the
OSI model ... do you have exemple of such soft that permits to do load
balancing on multiple NICs ?

Thx.

 

Well?,...then just do it. I'm not going to claim or even attempt to know
every secret little thing that someone somewhere out in internet land
figured out and wrote it in some article that I probably would never know
about unless someone told me it was there.

However if this was a very successful way of doing it than it probably would
be shouted from the mountain top and everyone would know about it. Since my
contacts at MS have never mentioned it to me,..and we've been in plenty of
conversation where they could have,...I am sceptical of how well it would
work. This article give really no details about how it behaves and under
what conditions, so I suspect there are plenty of "gottcha's" just waiting
to bite you.

I'll have to pass the link along to my friends at MS and see what they say
about it.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

 

It is called Nic Teaming and only works with Nics (and Drivers) that are
designed to do that. It runs two nics against the same connection (not two
different connections) so it will not let you use two ISPs that way you want
to. You can use it with a single connection to a single ISP.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

 

Actually I think you're right, I dig a litlle deeper and it seems that the
key in the registry they're talking about only affects the answers to Netbios
name request ... so yes it could do load balancing, but only in a pure
windows context and if links are on the same network.

See the following for more details :

http://technet2.microsoft.com/windo...8024-447b-873f-6eb35d79f9531033.mspx?mfr=true

But actually i'll be glad to have the answer of your microsoft's contact on
the subject ...

Thx again.

Julien.

 

He said it does not work with MS's Firewall product, ISA Server (he's on the
ISA Server team). But he didn't say anything about it in a generic sense. I
prodded him a little more, but if he doesn't have much else about it there
is one or two others outside of (but close to) MS that I can ask.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

 

Ok, interesting ... Im waiting for the answers of your other sources.

Thx.

Julien.

 

Here's his quote from the second reply he sent to me. I have not looked at
the KB articles he mentioned yet.

----------------
The net effect of it is during ARP, the system will respond with a random IP
associated with the machine.

It's a "poor-man's" LB technique that is really far less functional than
even RR DNS; much less NLB.

Check out MSKB 131736, 161425, 314053.
------------------


--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.