TWC (AS11351) blocking all NTP?

John R. Levine johnl at iecc.com
Mon Feb 3 20:29:21 UTC 2014


>> It seems thata hosts sending large amounts of NTP traffic over the
>> public Internet can be safely filtered if you don't already know that
>> it's one of the handful that's in the ntp.org pools or another well
>> known NTP master.
>
> Speaking as one of the 3841 servers in the pool.ntp.org pool, I'm happy to be 
> described as a "handful," something my mother used to say, but I do feel 
> obligated to point out that it's a pretty big handful especially if you want 
> to be fiddling ACLs on an hourly basis which is pretty much what it takes.

I was thinking that the ntp.org servers on any particular network are a 
small set of exceptions to a general rule to rate limit outgoing NTP 
traffic.

Regards,
John Levine, johnl at iecc.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. http://jl.ly



More information about the NANOG mailing list