[c-nsp] Multihoming

[Keegan Holley]

One last comment.  There are alot of people suggesting that you find a way
to advertise the /29 to the other ISP.  This is not possible.  The ISP that
gave it to you probably isn't willing to de-aggregate it when sending it to
the internet and the ISP that needs to accept it probably doesn't accept
blocks under a certain size to keep their routing table sizes under control.
 If you look at a route server in another AS you'll probably only see a /21
or better that contains your block.  ISP's normally advertise aggregates
only unless the customer was assigned a large block (/24 or better for most)
and requested that they do so.  Then they advertise both.


On Wed, Sep 15, 2010 at 12:30 PM, Keegan Holley
<keegan.holley at sungard.com>wrote:

> It looks like this subject has been beat to death so I'll skip the usual
> about obtaining a /24 form ARIN and a public ASN.  Global load-balancing is
> an option as it allows you to fail over your DNS entries to the second
> providers IP space.  This pretty much negates the need for BGP if all you
> were using it for was failover.  There are also companies that offer global
> load-balancing as a service so you don't have to worry about managing the
> box itself.  It's DNS based so the load-balancer itself can be anywhere in
> the world technically.  Redundancy is usually taken care of as well.