[CentOS] Advice in Time Sync

Wed Jan 15 17:56:04 UTC 2014
SilverTip257 <silvertip257 at gmail.com>

On Wed, Jan 15, 2014 at 5:53 AM, John Doe <jdmls at yahoo.com> wrote:

> From: John R Pierce <pierce at hogranch.com>
>
> >>  How to set up timing if NTP was block by ISP?
> > your ISP doesn't have their own timeserver you can access??
> > I've never heard of an ISP blocking ntp protocol, unless they are
> > blocking /everything/ but web and email via proxy, whereupon they aren't
> > really an internet service provider, they are just a web-n-mail service
> > provider.
>
> Maybe related to the (recent?) DDOS using ntp servers...?
>

Sounds likely.
ACLs like that are bad practice, but some people can get overzealous.
 Hopefully they're only temporary until the hosts running NTP have been
further secured.

http://blog.cloudflare.com/understanding-and-mitigating-ntp-based-ddos-attacks

It is probably a good idea to call and complain to your ISP if this is
happening to you.


As others mentioned, the OP might be able to sync time off their ISP's NTP
servers (if provided).
Or go with a GPS time source as John Pierce suggested.


First DNS attacks thanks to dns recursion, now NTP attacks due to time
servers... ;)


>
> JD
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---~~.~~---
Mike
//  SilverTip257  //