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Excessive load on NTP servers

news.ntppool.org

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Re: Excessive load on NTP servers

#51

Post by scurvy »

unethical_ban wrote: post #44
Declanomous wrote: post #12

For whatever reason, ntppool.org is blocked at my work. And of course, you don't get the page that states why when the website is served via https. Not that I need to see the page to know it was either blocked for "hacking" or "entertainment", and I'm guessing it's not entertainment. Edit: This probably explains why our clocks have been off by 45 minutes since Monday. I guess it will be entertaining to see how long i…

I don't know why an org would be blocking NTP. But ideally, IT would run their own NTP service (if the shop is big enough), block NTP to any other org, and sync their server with upstream. Similar to package management, DNS, etc. - self-host it all.

Blocking UDP 123 upstream is a common tactic to avoid participating in NTP DDoS botnets.

You're best off running your own NTP infrastructure that's isolated from the public Internet NTP servers if you want stable time sources. Put a CDMA NTP server in two locations, let them sync, and go. You can get cheap EndRun servers on eBay for a few hundred bucks.

Re: Excessive load on NTP servers

#52

Post by hyperpape »

skeptic2718 wrote: post #35
coleca wrote: post #30

FWIW my teenage daughter has been complaining about this latest Snapchat update for iOS the past couple days. It constantly crashes and causes the phone to reboot itself. Looking at Twitter, there's tons and tons of people reporting the same issue, so it seems pretty widespread. Wonder if it's related to this NTP issue.

Can apps cause iOS to reboot ? That's a bit shocking. I don't own an iPhone.

There still are kernel panics, they're just very rare.

Re: Excessive load on NTP servers

#53

Post by HCIdivision17 »

wjnc wrote: post #37
Declanomous wrote: post #32

Earlier quoted context omitted.

I got told off for diagnosing issues in the past. The IT director is a megalomaniac and interprets it as a challenge to his power. The only time I offer suggestions now is when one of his employees specifically asks me for help. Edit: I realize "got told off" didn't really capture what happened. I came in early one day and noticed we were having a dns issue. I manually refreshed my DNS cache and it started to work. I…

What kind of firm are you in (and perhaps more important: country/culture)? I've actively been a friendly pita wherever I worked and always found people to help search for answers, even if the question was not really in the line of work. Have a discussion related to tax and payrolling going on right now. Couldn't make sense of company policy even when reading / quoting the law (ianal). Still the surroundings stay fri…

I really like the term "friendly pita". When people complain about tech support being unhelpful, I've often found the opposite. Be genuinely friendly and relentless and I've found even incompentent people will fix things. Which I also genuinely appreciate.

Sincerity helps, both as a shield and as a way to diffuse the inevitable frustration that comes from troubleshooting tech.

Of course, I've got a strong force of will, too, so I tend to mix poorly with charlatains like the grandfather's post. I really feel for the souls who have to work under that jerk.

Re: Excessive load on NTP servers

#54

Post by metaphorm »

Declanomous wrote: post #32
Twirrim wrote: post #26

Earlier quoted context omitted.

> I guess it will be entertaining to see how long it takes for IT to figure this one out. Why not just tell them. What have you got to lose? Hell, blame your charitable spirit on the holiday season if you must.

I got told off for diagnosing issues in the past. The IT director is a megalomaniac and interprets it as a challenge to his power. The only time I offer suggestions now is when one of his employees specifically asks me for help. Edit: I realize "got told off" didn't really capture what happened. I came in early one day and noticed we were having a dns issue. I manually refreshed my DNS cache and it started to work. I…

where do you work, and more importantly, why do you still work there?

Re: Excessive load on NTP servers

#55

Post by icameron »

Declanomous wrote: post #32
Twirrim wrote: post #26

Earlier quoted context omitted.

> I guess it will be entertaining to see how long it takes for IT to figure this one out. Why not just tell them. What have you got to lose? Hell, blame your charitable spirit on the holiday season if you must.

I got told off for diagnosing issues in the past. The IT director is a megalomaniac and interprets it as a challenge to his power. The only time I offer suggestions now is when one of his employees specifically asks me for help. Edit: I realize "got told off" didn't really capture what happened. I came in early one day and noticed we were having a dns issue. I manually refreshed my DNS cache and it started to work. I…

If a cached DNS record expired it would not be a problem. If a bad or old record was cached before TTL, clearing your cache works to update it. Maybe ITs ego didn't like your terminology of DNS cache being expired, and telling them theirs is- by definition expired records get looked up again because they no longer exist locally. As former IT it was mildly irritating to get unsolicited advice, But still it sounds like a redicilous over reaction on ITs part. I'm assuming you didn't actually clear a local IT managed server's local DNS cache.

Re: Excessive load on NTP servers

#56

Post by andruby »

leesalminen wrote: post #36
Declanomous wrote: post #32

Earlier quoted context omitted.

I got told off for diagnosing issues in the past. The IT director is a megalomaniac and interprets it as a challenge to his power. The only time I offer suggestions now is when one of his employees specifically asks me for help. Edit: I realize "got told off" didn't really capture what happened. I came in early one day and noticed we were having a dns issue. I manually refreshed my DNS cache and it started to work. I…

I encountered a similar IT manager in high school. I kept telling him that netsend wasn't locked down and that any user could run a .bat. He told me I was wrong. So, I wrote a .bat with a netsend command and emailed it to all staff. Multiple staff clicked on the attachment. Once they figured out it was me, they made me start a computer club with the IT manager as the supervisor of the club. First order of business wa…

> Once they figured out it was me, they made me start a computer club with the IT manager as the supervisor of the club. First order of business was locking down .bat execution.

That seems like a great way to handle this situation. Some ignorant other schools might have kicked you to the curb because you were spreading "malware".

Re: Excessive load on NTP servers

#57

Post by Declanomous »

twic wrote: post #39
Declanomous wrote: post #32

Earlier quoted context omitted.

I got told off for diagnosing issues in the past. The IT director is a megalomaniac and interprets it as a challenge to his power. The only time I offer suggestions now is when one of his employees specifically asks me for help. Edit: I realize "got told off" didn't really capture what happened. I came in early one day and noticed we were having a dns issue. I manually refreshed my DNS cache and it started to work. I…

Have you thought about getting a new job, for someone who is not a nutcase?

Currently looking. I finally came to my last straw recently.

A coworker sent me an email because some data I was in charge of adding to the system was missing. I looked, and somehow data in our database had gone missing. I use the data to add information to another database, and that database had the information in it. So somehow he managed to lose information in SQL Server.

A few weeks later, my boss brought me in to his office because about 25k rows had incorrect information. I went to check my notes, and all of my notes from a period of 10 days were missing. I had been creating a changed file log (because files have been lost in the past), and I could see I had created notes during those dates, but they didn't exist anywhere.

The only evidence I had done my job at all during that time were the emails I sent to other people. (Thankfully Microsoft hosts these, so the IT director can't mess it up.) I had sent somebody an email that basically said "I found error [x], but I fixed it."

For a little while I was questioning whether I was insane. I mean, I would never have believed it was possible for data that you've added to an ACID database to just disappear. If you can't trust ACID principles, what can you trust?

Re: Excessive load on NTP servers

#59

Post by LoSboccacc »

skeptic2718 wrote: post #35
coleca wrote: post #30

FWIW my teenage daughter has been complaining about this latest Snapchat update for iOS the past couple days. It constantly crashes and causes the phone to reboot itself. Looking at Twitter, there's tons and tons of people reporting the same issue, so it seems pretty widespread. Wonder if it's related to this NTP issue.

Can apps cause iOS to reboot ? That's a bit shocking. I don't own an iPhone.

psh, iOS can be rebooted from safari by web pages - just send them enough images with 3d transform + filters and watch the memory allocator kill the whole system trying to compose the thing.

Re: Excessive load on NTP servers

#60

Post by cuonic »

easytiger wrote: post #2

Wait.. they are saying the app itself is making NTP requests? > Confirmed - starting up the iOS Snapchat app does a lookup to the domains you listed, and then sends NTP to every unique IP. Around 35-60 different IPs. Hmm. Is that a fraud prevention thing or something? No way on earth a user app should be getting its own time

Snapchat have a lot of "fraud protection" in the form of time sensitive tokens hashed with secret keys generated by strange .so libraries. This is used to keep third party apps from using their API, obviously a lot of user's devices have incorrect clocks, so when they reduced the secret token time frame lots of users probably started getting API errors, so this is their attempt at a solution.
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