Re: Heads up: Long AS-sets announced in the next few days

[James <haesu () towardex com>]

On Thu, Mar 03, 2005 at 02:28:43PM -0800, David Schwartz wrote:

[ snip ]

>       Every piece of BGP documentation I have ever seen says that this attribute
> documents the ASes that the route has actually passed through.
>
> > Do I need to get permission from Sprint before I include 1239:100 as a
> > community-string attribute on my own advertisement, too?
>
>       You certainly need their permission before you can advertise routes that
> falsely came to have passed through their network! 

What kind of specific _technical_ issue do I create by prepending another ASN
on AS_PATHs I advertise, without such "owner"'s permission?

> that you do need permission to attach someone else's community string to
> your routes and that it would be considered at least terribly bad manners to
> use undocumented community strings from other people's ASes. (Documentation,
> of course, equates to permission.)

Please, that's ridiculous.

[ snip ]
 
>       I'm curious where you would draw the line then. And I'm curious what you
> think is the point of registering AS numbers at all, if it's okay to use
> other people's without their permission.

If you are concerned about accuracy of registration records, I would advise
that you ensure that your origin AS (aka the last ASN showing up before 'i'
on Cisco or 'I' on Juniper in show output) in the AS_PATH is accurate. I don't
see any technical pitfalls to include someone else's ASN in the transit path
to avoid that particular ASNs from seeing it, other than the fact that is
generally a frowned-upon or tasteless act to do.

-J