Question about AS Origin changes
fweimer at bfk.de
Fri Mar 25 08:53:16 CDT 2011
* Yaoqing Liu:
> 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.
This is expected if the upstream has a static route for the prefix (or
a route which redistributed from another routing protocol). This
could be a leftover from a non-BGP setup with the customer. Or this
could be some sort of backup procedure (perhaps prompted by the
instability of the BGP link).
Florian Weimer <fweimer at bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstraße 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99
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