r2 - 2007-09-14 - 01:18:28 - HarlanStennYou are here: NTP >  Dev Web > DevelopmentIssues > PoolCasting
NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p15 was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.

Please see the NTP Security Notice for vulnerability and mitigation details.

Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.


Sachim's original intent was to add a pool command that would tinkle a willing DNS server, parse what came back and prune the population for the three survivors. Code to prune the survivors and manage refresh is already done for manycast and would be easy to use with pool as well. I'm not sure he finished the code or what shape it is in now.

The manycast code wasn't easy. The trick is to age the population after acquisition at a rate corresponding to whether a candidate is the system peer, among the survivors or not. Also considered is whether the stratum is below the floor or above the ceiling, which is useful to modulate the scheme, like protect the primary servers, etc.

Dave Mills

Related Topics: NewNtpConfFormat#Allow_configuration_of_up_to_N_I

-- DannyMayer - 08 Aug 2007

Edit | WYSIWYG | Attach | Printable | Raw View | Backlinks: Web, All Webs | History: r2 < r1 | More topic actions
SSL security by CAcert
Get the CAcert Root Certificate
This site is powered by the TWiki collaboration platform
IPv6 Ready
Copyright & 1999-2022 by the contributing authors. All material on this collaboration platform is the property of the contributing authors. Ideas, requests, problems regarding the site? Send feedback