>> This approach may not be as effective as you think. In a typical ntpd >> setup with multiple upstream NTP servers, ntpd doesn't really care if >> one of the upstream servers goes insane. It's simply marked as bad, and >> the other servers are used instead. However, this doesn't reduce the >> traffic to the bad server at all -- it might even slightly increase in >> certain situations. >> >> If you really must do something "active" instead of just not responding >> to the requests, please consider using Kiss-of-Death (KoD) packets. This >> is the official method of telling clients to stop sending requests to >> the server. Please read http://tools.ietf.org/html/rfc5905#section-7.4 >> >> ntpd can also output these KoD packets with the proper configuration, >> there's no need for any external software. > > Can anyone provide an NTP config that will give out KoD packets? I see > it mentioned in the man page, but no explanation of how to do it.
According to RFC4330 it is: 8. The Kiss-o'-Death Packet ... In general, an SNTP client should stop sending to a particular server if that server returns a reply with a Stratum field of 0, regardless of kiss code, and an alternate server is available. If no alternate server is available, the client should retransmit using an exponential-backoff algorithm described in the next section. Folkert van Heusden -- MultiTail är en flexibel redskap för att fälja logfilar, utför av commandoer, filtrera, ge färg, sammanfoga, o.s.v. följa. http://www.vanheusden.com/multitail/ ---------------------------------------------------------------------- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
