[c-nsp] BGP/private and public ASN mix trick

[Alex Balashov]

Nick,

As far as I know, as long as you're using private AS numbers to the 
customer, the announcement to a "real" eBGP peer should automatically
be rebranded with your originating AS.  I'm not sure if this is because
an IGP "origin" is somehow implied (which you have explicit), but I've
never seen a situation where announcing a prefix received from a customer
via private eBGP resulted in the private portion of the AS path being
announced.

This seems to be confirmed here:

    http://www.cisco.com/warp/public/459/32.html:

    "If the update has only private AS numbers in the AS_PATH, BGP removes
     these numbers."

Can't see any caveats...

Cheers,

-- Alex

--
Alex Balashov
Evariste Systems
Web    : http://www.evaristesys.com/
Tel    : +1-678-954-0670
Direct : +1-678-954-0671