DSCP on UDP port 123 and 53

While trying to debug some ports that appear closed at my ISP, I stumbled across this iptable rule in the OUTPUT chain, which doesn’t make much sense to me:

Target|Prot.|In|Out|Source|Destination|Options|Comment| |DSCP|udp|*|*|||multiport ports 123,53 DSCP set 0x24|-|

I know what DSCP is and of course these are ports for NTP and DNS, but why would DNS and NTP packets from the Omnia have DSCP set to 0x24 (dec 36) which accroding to https://linuxreviews.org/Type_of_Service_(ToS)_and_DSCP_Values means traffic class AF42 - which seems somewhat random.

I also couldn’t find where this rule comes from, i.e. what causes the rule to be created, since it’s not in the LuCI firewall config.

Any insight would be much appreciated.

How bizarre, I check today and the rule has disappeared. It disappeared just as mysteriously as it appeared. I did apply quite a large-looking update on HBL today and rebooted, so it could have either been a change in the update, or a left-over from some of my previous messing around (I can’t image what though) and a reboot got rid of it. Anyway, it’s gone now so I’m happy.

Oh, I think it’s better to specify in each thread that you’re using HBL. It’s not a branch expected for general usage.

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