Wireshark-dev: [Wireshark-dev] Display more digits for NTP packet's root dispersion
From: Martin Burnicki <[email protected]>
Date: Mon, 6 Aug 2018 11:19:22 +0200
Hi all,

actually the root dispersion field from an NTP packet is only displayed
with 4 digits after the decimal point, i.e. 0.1 ms resolution.

However, modern NTP servers may provide a better root dispersion. E.g.,
if only the LSB in the scaled integer of an NTP packet is set then this
means ~15 microseconds (0.000015 s) root dispersion, but this is
currently displayed as 0.0000 s, even though the real value is *not* 0.

The relevant piece of code seems to be the line

proto_tree_add_double(ntp_tree, hf_ntp_rootdelay, tvb, 4, 4, rootdelay);

in function dissect_ntp_std() in file dissectors/packet_ntp.c.

I tried to add this as a feature request to bugzilla, but was unable to
register with bugzilla. :-(

Martin Burnicki

Senior Software Engineer

MEINBERG Funkuhren GmbH & Co. KG
Email: [email protected]
Phone: +49 5281 9309-414
Linkedin: https://www.linkedin.com/in/martinburnicki/

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