Re: Comcast route server not reflecting their reality

[Ross Tajvar <ross () tajvar io>]

> Unlike AS2914 which purely interconnects with AS7922, it seems that AS3356
> also has direct interconnections to the various Comcast subsidiary
> networks which are hidden from the DFZ through no-export communities.


I'm curious how this works and why it's done this way. I have a friend who
has transit from AS7922 (the remote AS in his BGP sessions are all 7922),
but CenturyLink's looking glass shows an AS path of "33657 <his ASN>" and
includes the no-export community. Why is the AS path rewritten? What is the
design here?

-Ross