Route table growth and hardware limits...talk to the filter
Jon Lewis
jlewis at lewis.org
Sun Sep 23 15:23:01 UTC 2007
On Sun, 23 Sep 2007 michael.dillon at bt.com wrote:
>> Has everyone forgotten the "Tier 1 depeerings" of several
>> years ago? i.e.
>> If you were pointing default at C&W, PSINet, Cogent, or
>> Level3 when they each had or caused depeering issues, parts
>> of the internet ceased to be reachable. In such cases,
>> having full routes from multiple providers was the only way
>> to be automatically protected from such games.
>
> Not so. Anyone who had sufficient transit was also protected from
> the games. Lots of so-called regionals and tier-2 networks were
> shielded from this monkey-business. And, of course, they shielded
> their customers as well. A tier-1 network operator who operates such
> a fragile network becomes a single point of failure. And not just
> because of peering as the AT&T frame relay collapse shows.
I think you've completely missed what I said. If you were pointing
default at C&W (whether they were your only connection, or you were
"multihomed" but couldn't handle full routes, so perhaps you had customer
routes from each provider and default pointing at C&W) when they depeered
PSI, single homed (or similarly configured non-full routes) customers of
PSI ceased to be reachable. A long time customer of mine was hit by this
(their business required communications with one or more single homed
PSI customers, and C&W was their sole transit). It was the driving force
behind their multihoming. Ever since, they've maintained 3 or more
transit providers and full routes from each.
----------------------------------------------------------------------
Jon Lewis | I route
Senior Network Engineer | therefore you are
Atlantic Net |
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