nanog mailing list archives

Re: Apple Catalina Appears to Introduce Massive Jitter


From: Mark Tinka <mark.tinka () seacom com>
Date: Fri, 30 Oct 2020 08:41:44 +0200



On 10/29/20 20:14, David Curado wrote:

I was curious, so poked at this... my results from a macbook pro 2019 running Catalina 10.15.3

sudo /usr/local/sbin/mtr -r 10.200.200.200

Start: 2020-10-29T14:09:08-0400
HOST: bos-mp36c                   Loss%   Snt Last   Avg  Best  Wrst StDev
  1.|-- 10.200.200.200             0.0%    10 11.9  63.7   9.0 340.2 104.1

sudo sysctl net.link.generic.system.hwcksum_tx=0
net.link.generic.system.hwcksum_tx: 1 -> 0
sudo sysctl net.link.generic.system.hwcksum_rx=0
net.link.generic.system.hwcksum_rx: 1 -> 0
sudo ifconfig en0 -rxcsum

sudo /usr/local/sbin/mtr -r 10.200.200.200

Start: 2020-10-29T14:09:43-0400
HOST: bos-mp36c                   Loss%   Snt Last   Avg  Best  Wrst StDev
  1.|-- 10.200.200.200             0.0%    10 19.8  13.6   9.8  20.9   4.5

So, seems to make things better. =-)

I tried it again this morning, on the off-chance that the stars didn't align yesterday. Same deal:

sh-3.2# sysctl net.link.generic.system.hwcksum_tx=0
net.link.generic.system.hwcksum_tx: 1 -> 0
sh-3.2# sysctl net.link.generic.system.hwcksum_rx=0
net.link.generic.system.hwcksum_rx: 1 -> 0
sh-3.2# ifconfig en0 -rxcsum

Marks-MacBook-Pro.local (172.16.0.239) 2020-10-30T08:39:44+0200
Keys:  Help   Display mode   Restart statistics   Order of fields quit
Packets               Pings
 Host Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. 172.16.0.254 0.0%    28    1.9  28.7   1.9 218.9  56.1

Mark.


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