Re: Enterprise Multihoming
"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 --
Most of the multi-homing talk has been about failover capabilities between different providers. What about the effects of multiple providers when neither has actually failed; such as different paths for inbound/outbound traffic. One provider may have better connectivity to x site whereas the other provider has better connectivity to y. (Or is this not as important as it used to be?) On Fri, Mar 12, 2004 at 09:15:55AM -0700, John Neiberger wrote:
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.
On Fri, 12 Mar 2004, Stephen Fisher wrote:
Most of the multi-homing talk has been about failover capabilities between different providers. What about the effects of multiple providers when neither has actually failed; such as different paths for inbound/outbound traffic. One provider may have better connectivity to x site whereas the other provider has better connectivity to y. (Or is this not as important as it used to be?)
Capacity and congestion isnt a (big) issue with bandwidth and circuits being so cheap, most corporates just need to know they can get their email and browse the web and whether it takes 70 or 140ms for data to cross the atlantic providing it pops up on their screen within a few seconds they're happy. So in this way I think the answer to your question is its not important to most multihomers but ymmv.. Steve
On Fri, Mar 12, 2004 at 09:15:55AM -0700, John Neiberger wrote:
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.
participants (3)
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John Neiberger -
Stephen Fisher -
Stephen J. Wilcox