... because it's hosted on the cloud and you have no amount of free bandwidth with your vps ?
Why is my NTP server costing $500 per year? Part 1 (2014)
21–30 of 113 posts
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#22An interesting theory in one of the comments. > I wonder if Puerto Rico has run out of its pool of IPv4 addresses. After Europe and Asia, just this month Latin America as well, have exhausted their IPv4 pools, many local ISPs have resorted to using NAT to deal with the scarcity of addresses (of course, after years procrastinating IPv6 and pretending that this day wouldn't come about). Given that the source is a Puert…
I'm not understanding why NAT would cause it. I could see something like a misconfigured forwarding DNS cache causing it. Where it only queries pool.ntp.org once, and continues returning the result in the same order (with pivotal's ip at the top of the list) to a large number of querying clients. Then, perhaps, if there are a bunch of natted clients behind one ip? NAT, on it's own, without some other contributing fac…
NAT wouldn't cause it but hide that in fact those are many client all having the same source IP. Of course, that wouldn't explain why they observed a general increase in traffic.
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#23Because you use AWS and they charge insane fees for outgoing bandwidth.
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#24Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#25Earlier quoted context omitted.
Once you put an NTP server on the 'net, it's public - pretty much like most Web sites. Sure, there are reasonable expectations of decency like for anything in the Commons, but I don't think there's any legal defense against skunks at the picnic. IIRC, the university called Netgear out for doing something stupid and disruptive, and Netgear stopped doing it. The second best possible scenario, I guess.
> Netgear stopped doing it. Netgear issued patches for the devices. Most people never update their server firmware, and we're talking about over 700,000 devices. The university still gets considerable traffic. https://en.wikipedia.org/wiki/NTP_server_misuse_and_abuse#NE...
Can't the university throttle non local connections ? (netgear could have provided the hardware ;)
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#26part 2: https://blog.pivotal.io/labs/labs/ntp-server-costing-500year...
I wish he'd explained somewhere how they leapt to examining virtualized NTP clients, or what they ultimately did (since there's no part 3 that I can find).
Virtualization and time sync have had notorious problems. One ugly work around was frequent NTP polling and adjustments. NTP has a min and max poll interval, and it determines how frequently it should poll automatically based on how far it sees drift happening. If it drifts pretty fast, it will quickly gravitate to the minpoll value, which is exactly what they show in their first graph: tons of polling at the minfrequency for certain hypervisors.
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#27I wonder if they somehow mistakenly joined their server to the region-specific pr.pool.ntp.org group[1]. At the moment, that pool exists, but has no servers in it.
So, if you were the only server in the pool, perhaps you would get a lot of Puerto Rican traffic?
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#28Reminds me of when Netgear decided to use the University of Wisconsin NTP servers as the default in their consumer products: http://pages.cs.wisc.edu/~plonka/netgear-sntp/
The most frustrating part of things like this, and that Snapchat issue, is the largest abusers could probably swallow the cost of their own NTP server usage as a rounding error to their bottom line.
It must be "rounding error" as an example for everything week on HN
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#29I'm not sure if I've missed it, but is the question (from the title) ever answered? The discrepancy between expected traffic volume and actual traffic volume is huge and seemingly unexplained.
Re: Why is my NTP server costing $500 per year? Part 1 (2014)
#30I'm surprised there are no comments about the fact that these guys decided to run NTPD on a VM.