Prioritizing traffic in a VLAN

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello!
In my home lab, there are two mini pc (Proxmox servers) and one TP-Link Archer C6 v3 with OpenWRT 24.10.
These two mini PC (1 gigabit network) are directly connected to the OpenWRT router via ethernet.
I created a dedicated VLAN to handle the traffic between these two host.
Can I set up prioritization rules for a specific traffic inside the VLAN? This traffic will not be routed.
Example: I would prioritize the corosync traffic (udp/5404, udp/5405, udp/5406)

In the past I used the package “sqm” to reduce the bufferbloat.

Moreover, “Network > Interfaces > Devices > VLAN Interface (Configure… button) > Advanced device options “ there are two settings regarding the QoS mapping, but I did not find an example to use them.

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Have I to use iptables to implement “DSCP”?

Thanks

2

So the traffic just passes the switch.

What's your issue?

3

Hi!
yes, my network traffic is passing the switch (layer 2), no routing is involved in this communication.
I would be sure, that some kind of traffic is priority
thanks!

4

No, switched traffic is only passing through the chip.
Yes you could force frames and packets through the CPU but that would be a huge performance penalty.

Again, what's the issue you are facing?

5

So far, no issue, it is an optimization!
It is possible to do this kind of configuration using a managed switch :slight_smile:
OpenWrt is very flexible, so I thought it would be possible!

6

The issue is that the CPU of these chips are usually to slow for i.e. routing traffic at line speed.
Switching within the same vlan is handled by hardware.
Not quiet sure what you try to optimize.

Regarding manged switches.
Its the same.
Only difference that many enterprise Grade switches are capable of some layer 3 features so inter vlan routing is possible at line speed too.
But switches should be switches and routers should do routing.

7

Thanks for this exchange of ideas and thanks for your support!
It is possible optimize the traffic in a VLAN using COS policies for example.
Do anyone have any experience with this kind of configuration on OpenWRT?

Thanks!
Federico

8

If you are still talking about the connection of two ethernet ports on the same router/switch then there is nothing to optimise as that is already a point-to-point link between the two ethernet ports handled by the switch fabric and it will run at the maximum ethernet speed regardless of other traffic

9

thank you :slight_smile:

10

You can look at implementing traffic shaping / traffic control (tc) on your two mini PCs like you asked about for the switch.