This week I noticed my traceroute from one AS I run to another had changed, it appeared that TeraGo was leaking one or more routes.
The hop in question is hop 8. TeraGo? That’s strange, they used to be an AS14866 transit provider, I wonder if this is related. I confirmed that my route received at AS62758 had TeraGo in the AS-PATH (6327 20161 22652 14866), and contacted Fibrenoire. Since traceroutes to other IP ranges advertised by AS14866 did not go through TeraGo, I immediately suspected an old prefix-list had been merged into TeraGo’s configuration.
A traceroute to another subnet:
Completely different path (6327 6939 14866). Shaw’s nearest peering point with Hurricane is in Chicago. TeraGo is a Shaw transit customer. Hence, Shaw would localpref routes received via their customer, TeraGo, higher, and prefer the longer path.
The reverse path (from AS14866 to AS62758):
This issue has not yet been resolved by TeraGO NOC yet, this post will be updated as the situation unfolds.
** Update: **
Issue was not resolved by TeraGO, and instead TeraGO was depeered by FibreNoire.