Expedited Forwarding dscp

[mibere]

Hi there and thanks for sharing your guide. I have a question regarding dscp.

You use

# Expedited Forwarding DSCP directive traffic
dscp 48

'Expedited Forwarding' (EF) is 46 and is recommended for NTP. NTPsec also sets it to 46 (101110).

Are there reasons or advantages to use 48 (Control / CS6) ?

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About nice in Improve Chrony process priority, using systemd, this chrony option may also be helpful: sched_priority

[tiagofreire-pt]

Accordingly to the RFC2474, the CS6 is equal to the 48 decimal value, and 110000 binary one.

Thanks for the hint about sched_priority, I'll take a look to see if could be advantageous on this kind of setup.

[mibere]

Correct, CS6 is 48. But, EF, what is recommended for NTP, used by NTPsec and also mentioned in chrony manual, is 46.
That's why I asked why you use or recommend a non-EF value :-)

Instead of nice you can give 'sched_priority 1' in chrony.conf a try.