BGP prefix filtering, how exactly? [Re: YouTube IP Hijacking]

Mon Feb 25 20:29:01 UTC 2008

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> Our own or our singlehomed customers' address space -- we would reject 
> such an advertisement.  The same inbound consistency check applies to 
> peers and upstreams/transits.
>
> If it's someone else's or a more specific or the same prefix as our 
> multihomed customers -- we accept it.  There isn't anything else we 
> can do in practise which would not hurt legitimate routing..
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What do you do when one of your multi-homed customers on your IP space has
an outage on their connection to your network?  How would your customers
then reach that customer? 

Although this wouldn't be THAT BIG of a deal for small networks, if say a
larger or a Tier-1 provider practiced this (AFAIK, the only somewhat large
network to do this is, believe it or not, PCCW), your customer would
experience a major outage.

There must be a better way.  :)

> Pekka Savola

Regards,

Randy