Internet vulnerabilities

Fri Jul 5 13:05:44 UTC 2002

On Fri, 5 Jul 2002 13:36:49 +0100 (BST)
 "Stephen J. Wilcox" <steve at opaltelecom.co.uk> wrote:
> 
> Doesnt announcing the same routing prefix into BGP from multiple locations do
> the same thing without needing a new range or enhancement in IGMP etc ?
> 
> We do this in IGP currently..
> 
> Steve
> 

As I see it, the problems with doing this in BGP are

- it's static - no failover. If AS 701 and AS 1239 are both
announcing a route to foo, and your preferred route is "through" AS701,
and the AS701 foo goes down, then you do not
automatically switch over to the AS1239 foo, even if you could reach it.

- there is no way to have multiple anycast addresses within an AS

- load balancing is tough

These may all be solved, though... it's hard to tell without a protocol
description.

Regards
Marshall Eubanks

> 
> 
> 
> 
> On Fri, 5 Jul 2002, Barry Raveendran Greene wrote:
> 
> > 
> > 
> > FYI - for those scratching their heads on "anycast" .....
> > 
> > I just pushed out a paper on anycast by Chris Metz. Good foundation
> > material.
> > 
> > http://www.cisco.com/public/cons/isp/essentials/ip-anycast-cmetz-03.pdf
> > 
> > > -----Original Message-----
> > > From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu]On Behalf Of
> > > Bill Woodcock
> > > Sent: Friday, July 05, 2002 4:56 AM
> > > To: Marshall Eubanks
> > > Cc: nanog at merit.edu
> > > Subject: Re: Internet vulnerabilities
> > >
> > >
> > >
> > >     > But the only IPv4 anycast
> > >     > that I know of does use MSDP :
> > >     >
> > > http://www.ietf.org/internet-drafts/draft-ietf-mboned-anycast-rp-08.txt
> > >     > Is there a different proposal ? What's the RFC / I-D name ?
> > >
> > > You seem to be confusing anycast with something complicated.  It's not a
> > > protocol, it's a method of assigning and routing addresses.
> > >
> > >                                 -Bill
> > >
> > >
> > >
> > 
> > 
> 