[BBLISA] using multiple ISPs

[Tom Metro]

Alex Aminoff wrote:
> My suggestion: get 2 of the cheapest residential connections you can
> find and set up a router to switch between them as one or the other is
> down.

Reliability of the connection is not a top concern. I think the area
ISPs have a pretty good track record in that respect, and for those
offering both commercial and business class service, the low-end
commercial infrastructure is largely the same, and thus no better or worse.

Using more consumer-grade connections just means dealing with more
arcane port blocking rules, bandwidth cap policies, and clueless support
people.

That's not to say having a backup service isn't a good idea. Perhaps
using the least restrictive consumer-grade service as a fallback. Though
even at $50/moth it may be hard to justify the cost. You're paying
$600/year as insurance against down time. That might be worth it
(depending on what lost business will cost you) if you consider the
worse case scenario: multiple days of down time from your existing
provider, and multiple days of lead time to get a replacement service.
(A middle ground might be to have a "warm spare." Get a backup provider
installed, and test it for a few months, then shut it down. Chances are
good that if you need it, it could be brought up with just a phone call
and less than 8 hours of delay.)

If you wanted to do this, I have seen support for multiple WAN
connections added to open source router firmware, like Tomato USB, and
likely readily available for anything higher-end.


> You asked about static IPs however. That is thornier. You could probably
> rig up something with 2 bad providers as I suggested using dynamic DNS...

Yes, but as Rich noted about his setup, anything I'd consider
self-hosting could tolerate some down time.


Rich Braun wrote:
> One of the earlier suggestions was to run a pair of connections for 
> improved outage resilience, but unless you go full-on BGP I don't think 
> you'll achieve it for inbound services...

That's my understanding as well, with some exceptions: 1. if you are
self-hosting a web app, and having a "man in the middle" isn't a privacy
concern, you can front it with a proxy residing in the cloud, 2. you
could use a monitoring service that does fail-over in DNS (probably what
Alex was getting at), 3. use the VPN tunnel model, with the VPN
end-point being public, so if the primary link dies, you just reconnect
the VPN on the backup.

 -Tom

-- 
Tom Metro
The Perl Shop, Newton, MA, USA
"Predictable On-demand Perl Consulting."
http://www.theperlshop.com/