Merge several ISP connections..

Hi,

We have three different internet connections from different ISPs due to
several reasons.

Would it be possible to set up a linux box with 4 NICs, one for each ISP
connection and one as output which would give us the approximate sum of all
three with regard of bandwidth...?

Thanks for comments and info

Tor

Geir Holmavatn wrote:
> Hi,
>
> We have three different internet connections from different ISPs due to
> several reasons.
>
> Would it be possible to set up a linux box with 4 NICs, one for each ISP
> connection and one as output which would give us the approximate sum of all
> three with regard of bandwidth...?

http://lartc.org/howto/lartc.rpdb.multiple-links.html
Note the comment (very brief and cryptic) about masqing the lan IPs.

and look at this (search for the word "equalize")
http://www.policyrouting.org/PolicyR.../CH05.web.html

and this to round things out:
http://linux-ip.net/html/adv-multi-internet.html

Note that it may not work just as you want or think it will, eg., UDP
:-)
You will likely need to tweak the instructions for your needs.

hth,
prg

> Would it be possible to set up a linux box with 4 NICs, one for > > each ISP

>> http://lartc.org/howto/lartc.rpdb.multiple-links.html
>> Note the comment (very brief and cryptic) about masqing the >> lan IPs.

<snip>

prg is right. Just to add him - for a bigger picture, you might try
googling the net with the keyword "multihoming". When you connect your
network to two or more different Internet service providers (ISPs) or
for ISP's it's "upstream providers", that is multi-homing. Mostly BGP
is used for a bigger perspective.

ISP's generally don't share their autonomous system (AS) with home
users like you and me, but it's not a must rule. For that you might
need to install Zebra or another BGP-capable routing daemon in your
linux box. Your friendly ISPs might help you with that.


--
Raqueeb Hassan
Bangladesh

"Geir Holmavatn" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi,
>
> We have three different internet connections from different ISPs due to
> several reasons.
>
> Would it be possible to set up a linux box with 4 NICs, one for each ISP
> connection and one as output which would give us the approximate sum of
> all
> three with regard of bandwidth...?

If all you're after is throughput figures then the answer is yes but has
some complex considerations.

It really depends on what you use each of the links for because the only way
to give traffic figures is for the traffic to pass through the Linux box so
you would have to configure a firewall ruleset to match your exact setup.

If rather than balancing all load you say, used one connection for web
access, one for a static IP forwarding to a service in your network and one
for mail then this could be fairly easily accomplished. If you wish to
accomplish some form of redundancy and/or speed increase (being able to use
bandwidth from more than one connection) then this would require some quite
complex configuration. Sources of documentation for multi-honing are
mentioned elsewhere in your replies.

Once you have got the traffic flowing (shaped as desired) through your Linux
box you can then either setup accounting firewall rules to read, count the
traffic totals periodically for eth0,1,2... or run some other form of
standalone or SNMP based traffic analyser.

Have you considered a possibly simpler option - routers for each of the
connections doing whatever it is they do but supporting SNMP and then using
MRTG or similar to gather stats from them? I only ask because if you do
indeed want to multi-hone your network to protect redundancy then you're
introducing a big single-point-of-failure in the Linux box itself.

HTH,

Dave.