QoS marking (DSCP or PCP) of traffic?

[Mads]

Is there a way to implement QoS marking, either using DSCP (layer 3) or PCP (layer 2), on an Linux RT/LabVIEW target?

[BradM]

You can use iptables to mark traffic meeting certain criteria for handling upstream. If you need to control/shape traffic on the target itself, you will need to install/configure some different tools (not sure if they are on the feeds for installation, though)

[MarcosPires]

Hello,

Based on the NI Linux Real-Time Security User Guide.pdf I could use iptables commands to setup filter, but the command to change QOS DSCP (Differentiated Services Code Point) returns error. According to some Linux the forums DSCP may not be implemented on kernel requiring recompile it. Someone already used iptables on NI Linux RT to change DSCP?

This is the command I'm trying to use:

iptables -t mangle -A OUTPUT -o eth0 -p udp --dport 60002:60003 -j DSCP --set-dscp 46

or in a simpler way:

iptables -A INPUT -j DSCP --set-dscp 46

This is the received error in both cases:

iptables: No chain/target/match by that name.

Linux Forum indicating that it may be necessary to recompile kernel changing some configurations:

https://serverfault.com/questions/523731/how-to-fix-iptables-no-chain-target-match-by-that-name

Thanks.