[nsp] set as-path tag

[Ryan O'Connell]

On Tue, 3 Sep 2002 15:52:03 -0400 Jay Borkenhagen <jayb@braeburn.org> wrote:
> Anyone out there have any experience with Cisco "set as-path tag"?
[snip]
> I am checking with Cisco contacts as well, but while I wait for that
> response let me check with you folks, too.  I'm curious how long
> that feature has been around, what caused Cisco to put this in (rather
> than just making "set as-path prepend XXX" do the job in BGP network
> statements as well as inbound/outbound neighbor route-maps), whether
> there's any way to specify an as-path longer than a single ASN, bugs,
> gotchas, etc.

It's been in IOS since the early days of IOS BGP, 11.2 certainly but
possiblyearlier. CCO suggests it's been around since 11. 0 but that may
just be the set as-path prepend form of the command. It's certainly nothing
new - it's mentioned in Doyle Vol.II and IIRC also Halabi. 

I've no idea if it is of anything more than historical interest these days.
Certainly no one I know would redistribute BGP into an IGP and back on the
'net but someone might be using it on a private BGP network. The original
use of the command was so that you could do BGP-IGP-BGP redistribution and
not have to run BGP on all your devices.

Having said that I should be careful making statements about what people
will and won't do with BGP - it's quite flexible and there are a lot of
unusual uses of it about!

-- 
      Ryan O'Connell
Mail: ryan@complicity.co.uk
  CV: http://www.complicity.co.uk/ryancv.pdf
      CCIE #8174