Re: [Ntp] Antw: [EXT] Re: WGLC on draft‑ietf‑alternative‑port‑01

Hal Murray <halmurray+ietf@sonic.net> Sat, 31 July 2021 05:18 UTC

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From: Hal Murray <halmurray+ietf@sonic.net>
In-Reply-To: Message from Danny Mayer <mayer@pdmconsulting.net> of "Thu, 29 Jul 2021 15:12:45 -0400." <315bacee-255f-b517-a149-dc37ae9e0999@pdmconsulting.net>
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> So how would using an alternative port make a difference?

Because the filters are looking for UDP port 123.  The smart ones do a length 
check and let 48 byte packets througg.  The dumb ones just nuke them all.

The recent discussion has focused on middleware.  It also happens on transit 
links.

I have a pool server in London.  The monitoring station in the US frequently 
kicks it out of the pool because it can't verify that it is responding.

We had significant troubles during the early NTS hackathons.  NTP packets with 
NTS extensions didn't get through.


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