[Ntp] Antw: Re: New I-D: NTP Port Randomization (draft-gont-ntp-port-randomization-00.txt)
"Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de> Wed, 24 April 2019 06:12 UTC
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Date: Wed, 24 Apr 2019 08:12:40 +0200
From: Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
To: mlichvar@redhat.com, Fernando Gont <fgont@si6networks.com>
Cc: "ntp@ietf.org" <ntp@ietf.org>
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Subject: [Ntp] Antw: Re: New I-D: NTP Port Randomization (draft-gont-ntp-port-randomization-00.txt)
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>>> Fernando Gont <fgont@si6networks.com> schrieb am 24.04.2019 um 01:17 in Nachricht <890da574-a283-9ccc-28fc-19d500920d36@si6networks.com>: > On 23/4/19 10:48, Miroslav Lichvar wrote: >> On Fri, Apr 19, 2019 at 12:56:04AM +0200, Fernando Gont wrote: >>> On 18/4/19 14:36, Miroslav Lichvar wrote: >>>> The source port in client mode packets can be random and it can also >>>> change with each request, which might be recommended in the document. >>>> Most NTP clients do that. >>> >>> FWIW, I'm running ntpd 4.2.8p11@1.3728‑o on Ubuntu, and all packets use >>> src port 123. >> >> Yes, ntpd and ntpdate (without ‑q or ‑d) seem to be in the minority of >> clients using source port 123. > > Any clues whether in other cases they explicitly randomize the source > port, or rely on the kernel doing port randomization? Basically I think there are only two cases: 1) You care and pick a port number like 123 2) You don't care and use 0 as port number, causing the OS to pick one for you I see no point of explicitly selecting a random post, specifically when you can't be sure whether another process has picked that already, too. [...] Regards, Ulrich Windl
- [Ntp] New I-D: NTP Port Randomization (draft-gont… Fernando Gont
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Miroslav Lichvar
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Fernando Gont
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Miroslav Lichvar
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Fernando Gont
- [Ntp] Antw: Re: New I-D: NTP Port Randomization (… Ulrich Windl
- Re: [Ntp] Antw: Re: New I-D: NTP Port Randomizati… Fernando Gont
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Miroslav Lichvar
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Fernando Gont
- Re: [Ntp] New I-D: NTP Port Randomization (draft-… Miroslav Lichvar