Load Balancing Ethernet Cards
Dave Conners
connection to the internet. I'm interested in combining the three to form a
30Mbit connection if possible. Any help with this would be greatly
appreciated, especially if you could provide detailed instructions or a link
to such instructions. Thanks in advance.
-Dave
Nick Coons
Your subject mentions load balancing, which wouldn't be the same as
combining the three connections to make a single 30Mbps connection. Not
sure if the latter would even work, doing a single task at 30Mbps. I'm
going to go on the assumption, as it seems more realistic, that you want
to perform many tasks simoultaneously with a total combined bandwidth of
30Mbps.
I think this could be very easily setup using your routing table.
Divide the usable IP space (1.0.0.0 - 223.255.255.255) by three. So
you'd have traffic destined to 1.0.0.0 - 74.255.255.255 would be
assigned to one interface, traffic destined to 75.0.0.0 -
124.255.255.255 destined to the second interface, and traffic destined
to 125.0.0.0 - 223.255.255.255 destined to the third interface.
Some advice on this.. once it's setup, monitor the traffic. Just
because the IP space is dividing by three doesn't mean that traffic is
*evenly* divided by three. If you see that one interface is being used
significantly more than another, shuffle the size of the space around a
bit. Also, setup metrics so that there is fault-tolerance. If one
interface goes down, you'd be better off going down to 10Mbps than
losing access to 1/3rd of the Internet :-).
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Paul D.Smith
handle 10MBit total, shared between all the machines/routers etc. currently
trying to use it. Having three cards will not help as, in an ideal world,
each would effectively be running at 3.33MBit.
Paul DS.
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"Dave Conners" <dc...@hotmail.com> wrote in message
news:KEcg7.16180$_q.2...@typhoon.mw.mediaone.net...
Michael Pye
"Paul D.Smith" <p...@x-dataconnection.com> wrote
> I may be wrong but I thought that 10MBit meant that the entire network can
> handle 10MBit total, shared between all the machines/routers etc.
currently
> trying to use it. Having three cards will not help as, in an ideal world,
> each would effectively be running at 3.33MBit.
Hmm. Usually each machine is equipped for only a fraction of the total
network bandwidth, so for example, their network might have a 100Mb/s
capacity, but it is brought down to 10Mb/s for each workstation
connection... That way 10 workstations can be working full throttle at once,
of 100 workstations at an average of 1Mb/s flow...
MP
Mark H. Wood
Hmmm, you need to be a little more precise. Three taps on the same
coax. segment gives you 3.33mb/s (less some overhead) each. Three UTP
drops into the same multiport repeater gives you 3.33mb/s each. Three
UTP drops into the same switch with an 10mb/s uplink gives you
3.33mb/s each. Three UTP drops into the same switch with a 100mb/s
uplink gives you 10mb/s each. Three coax taps on different segments,
or three UTP drops into three different repeaters, gives you 10mb/s
each. If anybody else is using the same segment or repeater or
switch, then that may reduce the effective bandwidth.
You have to look at the entire path from sender to receiver, see how
quickly traffic moves through each segment, and see how many others
are contributing traffic. You could think of it as N faucets pouring
into a bathtub at 10mb/s each while the drain takes water away at 10
or 100 or 1000mb/s. If water is going in faster than it comes out,
you have options: you can buy more bathtubs and redistribute the
faucets; you can add drains to the bathtub; or you can live with the
overflowing. (Thanks to Gerald Weinberg for the bathtub model.)
--
Mark H. Wood, Lead System Programmer mw...@IUPUI.Edu
Make a good day.
Nick Coons
> > Hey, I have 3 ethernet cards in my system, each with a separate 10Mbit
> > connection to the internet. I'm interested in combining the three to form
> a
> > 30Mbit connection if possible. Any help with this would be greatly
> > appreciated, especially if you could provide detailed instructions or a
> link
> > to such instructions. Thanks in advance.
> I may be wrong but I thought that 10MBit meant that the entire network can
> handle 10MBit total, shared between all the machines/routers etc. currently
> trying to use it. Having three cards will not help as, in an ideal world,
> each would effectively be running at 3.33MBit.
The way he wrote it, it sounds like he has three *seperate* connections
to the Internet each at 10Mbps (either through seperate ISPs or all to
the same). These three connections are all on different networks, not
three connections to the same network. If they did all connect to the
same segment of a network, then the effect you described would be
correct.
Nick Coons
Limiting an individual workstation to 10Mbps is not usually the case.
If a LAN with a server and 10 workstations were connected, and one
workstation was in use, and it was only allowed 10Mbps, then 90Mbps
would be wasted.
Normally all the machines on a LAN are connected at the same speed
(either 10Mbps or 100Mpbs). This allows for full bandwidth utilization
if one or all workstations are in use. Some larger LANs are equipped
with servers connected at 1000Mbps. The reason for this is similar to
what you described above, but not to intentionally limit bandwidth, but
because the price to equip every workstation with a 1000Base NIC can be
outrageous.
Nick Coons
> >> I may be wrong but I thought that 10MBit meant that the entire network can
> >> handle 10MBit total, shared between all the machines/routers etc.
> > currently
> >> trying to use it. Having three cards will not help as, in an ideal world,
> >> each would effectively be running at 3.33MBit.
> > Hmm. Usually each machine is equipped for only a fraction of the total
> > network bandwidth, so for example, their network might have a 100Mb/s
> > capacity, but it is brought down to 10Mb/s for each workstation
> > connection... That way 10 workstations can be working full throttle at once,
> > of 100 workstations at an average of 1Mb/s flow...
> Hmmm, you need to be a little more precise. Three taps on the same
> coax. segment gives you 3.33mb/s (less some overhead) each.
Coax networks generally run at 1.2Mbps, divided by three leaves only
400Kbps.
> Three UTP
> drops into the same multiport repeater gives you 3.33mb/s each.
The only time dividing by the number of ports is accurate is if all
ports are in use simoultaneously.
> Three
> UTP drops into the same switch with an 10mb/s uplink gives you
> 3.33mb/s each. Three UTP drops into the same switch with a 100mb/s
> uplink gives you 10mb/s each. Three coax taps on different segments,
> or three UTP drops into three different repeaters, gives you 10mb/s
> each. If anybody else is using the same segment or repeater or
> switch, then that may reduce the effective bandwidth.
When it comes to switches, it depends on where the traffic is going.
On a single 100Mbps switch, computer A can communicate with computer B
at 100Mbps while computer C communicates with computer D
simoultaneously.
Mark H. Wood
[snippage]
[I wrote:]
>> Hmmm, you need to be a little more precise. Three taps on the same
>> coax. segment gives you 3.33mb/s (less some overhead) each.
>
> Coax networks generally run at 1.2Mbps, divided by three leaves only
> 400Kbps.
10base2 runs at 10mb/s just like 10base5 and 10baseT. Hence the "10".
What kind of network are you talking about?
>> Three UTP
>> drops into the same multiport repeater gives you 3.33mb/s each.
>
> The only time dividing by the number of ports is accurate is if all
> ports are in use simoultaneously.
If you are load-balancing across three ports then they are all running
concurrently. If you aren't load-balancing then why do you have
one box running into multiple taps on the same segment?
>> Three
>> UTP drops into the same switch with an 10mb/s uplink gives you
>> 3.33mb/s each. Three UTP drops into the same switch with a 100mb/s
>> uplink gives you 10mb/s each. Three coax taps on different segments,
>> or three UTP drops into three different repeaters, gives you 10mb/s
>> each. If anybody else is using the same segment or repeater or
>> switch, then that may reduce the effective bandwidth.
>
> When it comes to switches, it depends on where the traffic is going.
> On a single 100Mbps switch, computer A can communicate with computer B
> at 100Mbps while computer C communicates with computer D
> simoultaneously.
Well spotted. My assumption was that everyone on the downstream side
has business with the upstream side, but seldom if ever any business
with others on the downstream side. That is: A, B, and C all want
service from Y and Z but almost never talk to each other, and likewise
Y and Z have little to say to one another.
Like this:
A B C
| | |
------ | ------ (office/lab. space)
|||
switch
|
| (backbone segment)
|
switch
||
-- --
| | (server room)
Y Z
Nick Coons
> >> Hmmm, you need to be a little more precise. Three taps on the same
> >> coax. segment gives you 3.33mb/s (less some overhead) each.
> > Coax networks generally run at 1.2Mbps, divided by three leaves only
> > 400Kbps.
> 10base2 runs at 10mb/s just like 10base5 and 10baseT. Hence the "10".
> What kind of network are you talking about?
Hmm.. now that you mention it, I don't recall which network type. But
I remember using them a bunch about 8 years ago when LANtastic was
popular for small networks.
> >> Three UTP
> >> drops into the same multiport repeater gives you 3.33mb/s each.
> > The only time dividing by the number of ports is accurate is if all
> > ports are in use simoultaneously.
> If you are load-balancing across three ports then they are all running
> concurrently. If you aren't load-balancing then why do you have
> one box running into multiple taps on the same segment?
The original post (made a couple of weeks ago) had three connections to
three seperate segments, not to the same segment.
> Like this:
Right, that's how it'd generally be setup.
Ralf Quint
wrote:
>Hi Mark!
>
>> >> Hmmm, you need to be a little more precise. Three taps on the same
>> >> coax. segment gives you 3.33mb/s (less some overhead) each.
>
>> > Coax networks generally run at 1.2Mbps, divided by three leaves only
>> > 400Kbps.
>
>> 10base2 runs at 10mb/s just like 10base5 and 10baseT. Hence the "10".
>> What kind of network are you talking about?
>
> Hmm.. now that you mention it, I don't recall which network type. But
>I remember using them a bunch about 8 years ago when LANtastic was
>popular for small networks.
>
Maybe you have mistake this with the now extinct ArcNet????
Michael Pye
"Nick Coons" <nco...@dcs-home.com> wrote
> Limiting an individual workstation to 10Mbps is not usually the case.
> If a LAN with a server and 10 workstations were connected, and one
> workstation was in use, and it was only allowed 10Mbps, then 90Mbps
> would be wasted.
>
> Normally all the machines on a LAN are connected at the same speed
> (either 10Mbps or 100Mpbs). This allows for full bandwidth utilization
> if one or all workstations are in use. Some larger LANs are equipped
> with servers connected at 1000Mbps. The reason for this is similar to
> what you described above, but not to intentionally limit bandwidth, but
> because the price to equip every workstation with a 1000Base NIC can be
> outrageous.
Well, when the network I spoke of was begin set up it was to do with the
price of infrastructure, but it was a few years ago, so just divide your
speeds by 10 and you are there. The servers and the backbone run at 100Mbps,
but the workstations only have 10Mbps cards and connection sockets.
MP
PS. We are talking about a university hospital here with many servers and
thousands of workstations, each LAN had a total capability of 100Mbps, but
workstations were limited to 10Mbps each. The chance of much being wasted
except when the building is empty is fairly slim, especially if you add the
fact that almost all the workstations are standalone machines using the
network infrastructure for services rather than in a traditional
client/server model. They don't need more than 10Mbps each anyway...
Nick Coons
> >> 10base2 runs at 10mb/s just like 10base5 and 10baseT. Hence the "10".
> >> What kind of network are you talking about?
> > Hmm.. now that you mention it, I don't recall which network type. But
> >I remember using them a bunch about 8 years ago when LANtastic was
> >popular for small networks.
> Maybe you have mistake this with the now extinct ArcNet????
That's very possible.