Odd UUNET BGP announcements for interior netblocks

["David G. Andersen" <dga () lcs mit edu>]

We periodically see UUNET suddenly leak large numbers of what I can only
assume are interior routes, to quite a few peers, and then rapidly withdraw
them:

+---------------------+------+-------------------+------+--------+
| time                | type | prefix            | mask | aspath |
+---------------------+------+-------------------+------+--------+
| 2002-04-24 03:20:50 | A    | 208.254.255.0     |   24 | 1 701  |
| 2002-04-24 03:22:14 | A    | 208.254.255.0     |   24 | 1 701  |
| 2002-04-24 03:22:36 | W    | 208.254.255.0     |   24 | NULL   |
+---------------------+------+-------------------+------+--------+

... now you see it, now you don't.  A check with routeviews shows
that we're not the only one seeing such things.  For instance, from
AT&T's perspective:

+---------------------+--------+------+---------------+------+----------+
| time                | src_as | type | prefix        | mask | aspath   |
+---------------------+--------+------+---------------+------+----------+
| 2002-04-24 03:20:39 |   7018 | A    | 208.254.255.0 |   24 | 7018 701 |
| 2002-04-24 03:21:06 |   7018 | A    | 208.254.255.0 |   24 | 7018 701 |
| 2002-04-24 03:22:05 |   7018 | A    | 208.254.255.0 |   24 | 7018 701 |
| 2002-04-24 03:22:35 |   7018 | W    | 208.254.255.0 |   24 | NULL     |
+---------------------+--------+------+---------------+------+----------+

These seem to happen about once a month or so, typically at odd hours.
Is this a goof up, or some strange leakage during filter reconfiguration?
Anyone from UUNET care to clue me in?

Thanks,

  -Dave

-- 
work: dga () lcs mit edu                          me:  dga () pobox com
      MIT Laboratory for Computer Science           http://www.angio.net/