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j1simon

Member

From: Denmark

Registered: 2016-01-28

Posts: 189

SOLVED|Best way to specify "qdisc" values every time network (re)start

I'm trying this network configuration because my streaming server sometimes "jams" (it's a second or less) when playing something.
It is necessary to replace the root qdisc to cake diffserv4 with the command:

/sbin/tc qdisc replace root dev enp1s0 cake ethernet diffserv4 wash

But these changes are not sustained by rebooting the system.
What is the proper/optimal way to specify these changes in boot time?

Last edited by j1simon (2020-08-17 09:40:29)

j1simon

Member

From: Denmark

Registered: 2016-01-28

Posts: 189

Re: SOLVED|Best way to specify "qdisc" values every time network (re)start

I have created a systemd service to do this:

[Unit]
Description=Replace the root qdisc to cake diffserv4
After= network-online.target

[Service]
ExecStart=/sbin/tc qdisc replace root dev enp1s0 cake ethernet diffserv4 wash

[Install]
WantedBy=multi-user.target

It works but is this the optimal way?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,944

Re: SOLVED|Best way to specify "qdisc" values every time network (re)start

Sure why not?

You don't need to wait for network-online.target, network.target should suffice, but it doesn't make a practical difference as you just want that to be set whenever as long as it's set before you use the network.

j1simon

Member

From: Denmark

Registered: 2016-01-28

Posts: 189

Re: SOLVED|Best way to specify "qdisc" values every time network (re)start

It doesn't work well with systemd service. If the network is restarted, the tc qdisc cake is activated but with defaults: diffserv3 nowash.
It would be necessary for that script to be run every time the network is started, not just at system startup.

schard

Forum Moderator

From: Hannover

Registered: 2016-05-06

Posts: 2,152

Website

Re: SOLVED|Best way to specify "qdisc" values every time network (re)start

Have a look at BindsTo=.

Last edited by schard (2020-08-17 07:21:37)

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j1simon

Member

From: Denmark

Registered: 2016-01-28

Posts: 189

Re: SOLVED|Best way to specify "qdisc" values every time network (re)start

Have a look at BindsTo=.

Thanks, but it doesn't work. My system unit:

[Unit]
Description=Replace the root qdisc to cake diffserv4
Wants=network-online.target
After=network-online.target
BindsTo=network-online.target

[Service]
Type=oneshot
ExecStart=/sbin/tc qdisc replace root dev enp1s0 cake ethernet diffserv4 wash

[Install]
WantedBy=multi-user.target

j1simon

Member

From: Denmark

Registered: 2016-01-28

Posts: 189

Re: SOLVED|Best way to specify "qdisc" values every time network (re)start

Solved. In this case the use of a systemd unit it isn't useful. It is necessary use a NetworkManager Dispatcher script.
In the folder "/etc/NetworkManager/dispatcher.d/pre-up.d/" I have created this script:

#!/usr/bin/env sh
[[ $1 == "enp1s0" ]] || return 0
/sbin/tc qdisc replace root dev enp1s0 cake ethernet diffserv4 wash

Now it works even when the network connection restarts.