Hi, I''m building a set of networks for a chain of cyber cafes. The Internet connections are 512k ADSL links which work very unreliably. There are at least a couple of hours each day they do not work. Therefore the owner decided to put two of them in each network, choosing a different ISP to minimize the probability that both fail at the same time (which still happens). If one fails, we now can switch manually to the other. Now, of course, I would like to use the right interface for each connection, either the only one which is working, or which is being less used. All client machines are routed through a proxy server which also controls who may reach Internet at a given time. I have been looking for a solution to this problem for quite a while, but most methods seem to be designed to address the inverse situation, where one server can be reached by more than one links. Is there a way to do this with the Linux 2.4? Thanks in advance. -- Christoph Simon datageo@terra.com.br --- ^X^C q quit :q ^C end x exit ZZ ^D ? help shit .
Hi there,> I have been looking for a solution to this problem for quite a while, > but most methods seem to be designed to address the inverse situation, > where one server can be reached by more than one links. Is there a way > to do this with the Linux 2.4?I have the same problem. I found a message about something similar on this list (mail titled Re: [LARTC] Combining bandwith of two or more ADSLs ?, dated april 10, 2001) but this didn''t work for me: I once had traffic over 2 interfaces (2 pings to different systems) but after stopping and restarting the ping, they both took the same interface out. I also noted traffic coming in on interface 1 and going out of interface 2 (don''t know why). If I had sufficient hardware, I think that I would insert several extra PC''s with routing-software (www.zebra.org, since gated dumps core on me) and get BGP or OSPF: +--------+ +--------+ | adsl-1 | | adsl-2 | +--------+ +--------+ \ / \ / \ / \ / \ / \ / \ / +--------+ | proxy | +--------+ | | | +-----------------------+ | Lot of other machines | +-----------------------+ I did notice that when you have 2 BGP-routers both advertising a default gateway, the system only uses 1. If this one fails, it starts using the second but it won''t switch back when the original comes back up again. I have not yet played with OSPF but in theory, this should allow for some load-balancing too. Clemens Sibon -- Pettemerstraat 12A T r I p l e 1823 CW Alkmaar T Tel. +31 (0)72-5129516 fax. +31 (0)72-5129520 Automatisering www.triple-it.nl "Laat uw Net Werken!"
On Mon, May 21, 2001 at 03:36:50PM +0200, Clemens Sibon wrote:> I did notice that when you have 2 BGP-routers both advertising a default > gateway, the system only uses 1. If this one fails, it starts using the > second but it won''t switch back when the original comes back up again. I > have not yet played with OSPF but in theory, this should allow for some > load-balancing too.If you assign a higher metric to the second one then when the first one is available it will flush out the second one. Ramin> > Clemens Sibon > -- > Pettemerstraat 12A T r I p l e > 1823 CW Alkmaar T > Tel. +31 (0)72-5129516 > fax. +31 (0)72-5129520 Automatisering > www.triple-it.nl "Laat uw Net Werken!" > > _______________________________________________ > LARTC mailing list / LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/
On Mon, 21 May 2001 11:35:32 +0200 (MET DST) Arthur van Leeuwen <arthurvl@sci.kun.nl> wrote:> On Sun, 20 May 2001, Christoph Simon wrote: > > > I have been looking for a solution to this problem for quite a while, > > but most methods seem to be designed to address the inverse situation, > > where one server can be reached by more than one links. Is there a way > > to do this with the Linux 2.4? > > Yes there is. Look at the posts I did in october and november of last year > (sorry, don''t have the URL''s into the mailinglist archive handy). The > problem will be automatic monitoring of whether or not your uplinks are > indeed still up.I did do this right now, but couldn''t find a solution. That which came closest, seems to have problems when one link is down (is this still true with kernel 2.4.4?), which unfortunately is my case most of the time. OTOH, I''m receiving lots of emails of other persons looking for this solution. Would it be possible that some of those who worked on that in october/november share their experiences in form of a mini-howto? If not, I guess, a description of the basic strategy would be very helpfull, as most of us don''t even know where to start trying. -- Christoph Simon datageo@terra.com.br --- ^X^C q quit :q ^C end x exit ZZ ^D ? help shit .