North American Network Operators Group

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RE: multi-homing fixes

  • From: Dave Israel
  • Date: Tue Aug 28 12:16:17 2001

Sean, you male chauvinist pig. ;-)  Actually, the following is a 
general rant, and not aimed at Sean.

A BGP route seems to take approximately 155 bytes (based on "show ip
route summary" on a convenient GSR; YMMV).  So a singe BGP route, at
$1000 per 128 meg (that is, at the absurd markup a vendor might
charge), you're looking 1/8 of a cent per route per router.  That
doesn't count memory for a separate forwarding table; still, we're
not talking about a billable amount per router.

Now, if I am a service provider of any scale, and I do not accept your
specific announcements, I run the risk of taking a sub-optimal path to
you.  There are lots of acceptable reasons for this to be.  What if
you are transitioning from provider X to provider Y, and have been
given 60 days to renumber?  Should you renumber on Transition Day and
suffer the effects of waiting for nameservice?  Or if you do mistrust
your provider, or find it cheaper to connect to two smaller tier-3ish
providers than one tier-1ish to get the same distance from the sites
you need to reach?  As a provider, I want to be able to offer the best
connectivity to my customers, and even a little courtesy to the dear
departed.  I want to provide, and respect other people's provision of,
these services.

If you're not providing these services to people, then sure, filter
your BGP announcements.  On the other hand, if you're not providing
these services, and you're not multihomed (and unless you have a /19
or so, part of the problem, in which case you have no place to bitch),
what the heck do you need the table for?  Assuming you're a good
Internet player who has no need to be kind to your fellow providers,
filter and dampen and save your time and memory.  Heck, even if you
are being kind, dampen; there's no reason to let a madly flapping 
network give your iBGP mesh a heart attack.  But a stable route
providing intelligent path selection to a network your customers
may need to reach, or time for a site to renumber without any loss
of connectivity?  For an eight of a cent?  I mean, come on.


On 8/28/2001 at 08:41:40 -0700, Sean M. Doran said:
> "David Schwartz" <[email protected]> writes:
> | 	I'm not sure I believe that this tragedy of the commons exists where people
> | route on allocation boundaries. If I make Sprint carry an extra route just
> | for my little network, that helps all Sprint customers reach my little
> | network.
> Cool, so you can get them to contribute a fraction of the 50 cents you owe me?
> Since I live downstream from Sprint, I tell you what: I'll give you
> the first flap for free.   And that's a generous offer, given that
> your little network represents approximately zero percent of my traffic,
> and I doubt I'll be complaining to my other personalities that I can't
> get at your fascinating content without subsidizing your network's 
> globally-visible dynamicism.
> 	Sean. (who does, incidentally, subscribe to some pay-for-play
> 	       web sites, for example, which helps them pay for a part of THEIR
> 	       dynamicism.  i must remember to ask for a 50 cent * n discount 
> 	       at renewal time...)
> P.S.: the point here, since it's easy to miss, is that a clearing house
>       function is useful for containing complexity of negotiation, and 
>       is currently being done by the RIRs on behalf of their owners
>       business opportunity: a tool which reliably lets one decide if 
>       prefix x is worth carrying in all its flapping glory, or whether
>       it should be bitbucketed until a bill is paid

Dave Israel
Senior Manager, IP Backbone
Intermedia Business Internet