Routes and routing tables

Avi Freedman freedman at
Sun Apr 28 04:33:13 UTC 1996

> Sometimes more-specifics are needed to compete against more-specifics being
> incorrectly advertised by other people.  Sometimes folks _insist_ on cutouts,
> and you have to go route-to-route against them if you want to keep your block
> intact.  I hate this, it's bad business, I don't do it myself, I don't let my
> customers do it, but I've seen it often enough to have it be worth mentioning.

If you've got a larger block (say, a /16) and a customer with a /24 becomes
dual-homed and wants to split the incoming traffic on his links, you're
stuck advertising the /24 as well as the /16; otherwise, their 2nd provider
will always win for incoming traffic from most of the 'net...  However,
the 2nd path to a route consumes a LOT less memory than an additional

We do this for 1 customer right now, and possibly 1 in the near future.

Luckily, the demand for this is mostly limited to ISPs rather than 
other types of companies...


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