North American Network Operators Group
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Not so newbie BGP question...

  • From: John Fraizer
  • Date: Tue Oct 03 00:34:59 2000 
Can anyone offer any suggestions for the following:

ASNs changed to protect the guilty.

AS 65501 is a transit provider of AS 65502.

AS 65502 is a transit provider of AS 65503.

All three (65501, 65502 and 65503) peer to exchange customer routes (no
transit) via a regional exchange point.


|| = transit

| = customer routes only

Global internet
    ||
  65501-------Regional_Exchange
    ||            |     |
  65502------------     |
    ||                  |
  65503------------------




Problem:

65501 sees direct routes to 65503 and selects them as best at their
core. (They peer with the route servers of the regional exchange from
their core.)

Since the direct (exchange) route to 65503 is selected as the best path it
is passed throughout their network to the edges as the best path.  It
doesn't pass through their as-path access-list filters on the edge however
since 65503 isn't a TRANSIT customer of theirs and as such, the
65501_65502_65503 routes never get announced at the 65501 borders.

The regional exchange operates in transparent mode. (transparent AS,
transparent nexthop)

Is there a way to have 65501 see routes in it's core to 65503, yet
announce the 65502_65503 routes to its other bilateral peers on its
borders?



Any suggestions are greatly appreciated.

---
John Fraizer
EnterZone, Inc