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On Sun, 14 Sep 2014, Simon Avery wrote:
Also - why not take benefit from load balancing and effectively doubling your downstream (in multi-fetch uses like webpages) if it's easy?
It's not always that easy )-:An issue you'll find - and I've had it in the past - is that you go to a web site, the load balancer sends the first request via the first ISP connection, then you login in/authenticate, then the next request you send goes via the 2nd ISP - and then the remote site goes: "woa, you changed IP addresses, login again".
This happens especially with banks and some other ecommerce sites.There are ways to make is such that all data to a site is kept to one ISPs connection, but even then I've had issues when the remote sites use different servers to serve content - and if each of those servers use the same authentication, then that fails too. Again banks seem to be the worst for this sort of thing.
That's not perfect as then all accesses to that particular remote site will be cached into that one ISPs connection - so when everyone in the office accesses Dilbert, it all uses one ISP connection with the other sitting idle...
What you can do is arrange for the load balancing to work based on the source IP address - ie. the PC on the inside connecting to the outside, so that all transactions from that PC go via one ISP - until there have been no data transfered for some time then that PCs internal IP can go back into the balancing pool to work out which ISP connection to use for the next transaction - that's not perfect though and you still end up with situations like the above -either one ISPs line being saturated, or your time-out not being long enough so the remote site sees an IP address change and wants you to re-authenticate with it.
But apart from sites which authenticate on every transaction that sort of load balancing works relatively OK and is a cheap solution.
Gordon -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/listfaq