"Stephen J. Wilcox" <steve@telecomplete.co.uk> 3/12/04 9:06:38 AM
I dont agree that connecting to two+ upstreams makes you better. In
my
experience end networks have a couple of orders of magnitude more
downtime than
a PoP in any reasonably large ISP. Ie the percentage theoretical
improvement is
small.
In addition you seriously increase the complexity of your system,
chances are
you're using the cheapest kit you could find (or at least cheaper and
smaller
than what I would use).. its not great at BGP and may fall over when
you get a
minor DoS attack, you probably generate flaps quite a bit from adhoc
changes and
if you're announcing a /24 then thats going to get you dampened
quickly.. so you
actually create a new weakest link. Also most of the corporates I've
dealt with
take defaults rather than full tables.. so if the provider does have
an issue
you still forward the traffic, theres no failover of outbound
routing.
Even if you spend (waste) the money on some decent gear, you're on
your own and
when a problem occurs the ISPs are going to be less helpful to you
(not by
choice, I mean they dont have control of your network any more.. there
knowledge
of whats causing problems is limited to the bit that they provide to
you), so
chances are your problems may be more serious and take longer to
diagnose and
fix.
The above arguments are rather similar to the ones I heard on the other
discussion list I mentioned, and they were somewhat compelling.
IMHO avoid multihoming. You will know when you are big enough and you
*need* to
do it, if you're not sure or you only want to do it cause you heard
everyone
else is and its real cool then I suggest you dont.
In our case, we already are multihoming and I'm considering moving away
from that to a simpler solution. It's been my assertion that we didn't
need to multihome in the beginning. The decision was made at a level
higher than me. However, now that we have it I'm trying to determine the
pros and cons related to moving to a single provider.
Thanks,
John