We have a similar situation (RR + always-compare-MED off), and the BGP table version keeps changing at 1K/min (http://performance.cn.net:2003/). I suspect some route meet the criteria of IDR-oscillation draft. But in real world, it's very hard to pick up the pattern depicted in the draft from a huge log of debug bgp output.

It's actually quite trivial to identify. Have a look at: http://www.cisco.com/warp/public/770/fn12942.html Juniper syntax would result in the same..

1. How many time do our operator really find and affected by the problem depicted in draft-ietf-idr-route-oscillation-01.txt

I know of more than a few, and would bet that if additional folks took the time to look, they'd realize it was occurring as well.

2. From my experience, most flapping seems to be oscillation route which escaped the eBGP damping protection. And for this, we need adjust damping parameters from RIPE 220 to make up.

Nope. Dampening doesn't resolve this because it occurs intrA-domain.

3. Anyone see oscillation been magnified when injected into RR (cluster structure) ?

Not sure I understand what you mean by "magnified"? Have a look at the Cisco FN, it's useful in understanding and identifying the problem. -danny