Question about AS Origin changes

Yaoqing(Joey) Liu joey.liuyq at
Thu Mar 24 22:24:53 CDT 2011

Hi NANOG list,

I am wondering if anyone can give me possible reasons for some uncommon BGP
origin change activity.  What we see is that sometimes the origin for a
prefix seems to change from a customer AS to it upstream provider and back.
 In many instances the prefix simply switches back and forth for hours or
even days and sometimes very rapidly .  Below I’m including an example of
some of the activities I see.

Prefix 202.83.96/20 on border router 852)

At 14:10:56 Dec 04 2010, the BGP path with AS18106 as the origin
At 14:11:57,  the BGP path with AS9255 as the origin
At 14:14:27, the BGP path with AS18106 as the origin.


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