TWC (AS11351) blocking all NTP?

Jonathan Towne jtowne at slic.com
Sun Feb 2 04:03:19 UTC 2014


This evening all of my servers lost NTP sync, stating that our on-site NTP
servers hadn't synced in too long.

Reference time noted by the local NTP servers:
  Fri, Jan 31 2014 19:11:29.725

Apparently since then, NTP has been unable to traverse the circuit.  Our
other provider is shuffling NTP packets just fine, and after finding an
NTP peer that return routed in that direction, I was able to get NTP back
in shape.

Spot checking various NTP peers configured on my end with various looking
glasses close to the far-end confirm that anytime the return route is
through AS11351, we never get the responses.  Outbound routes almost always
take the shorter route through our other provider.

Is anyone else seeing this, or am I lucky enough to have it localized to
my region (Northern NY)?

I've created a ticket with the provider, although with it being the weekend,
I have doubts it'll be a quick resolution.  I'm sure its a strange knee-jerk
response to the monlist garbage.  Still, stopping time without warning is
Uncool, Man.

-- Jonathan Towne



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