ECN not working

[GANLIN TANG]

Hello:

I'm a new member in mininet, I try to make ecn working in the program, but it seem not work, the below is the code:

#!/usr/bin/env python

from mininet.net import Mininet

from mininet.cli import CLI

from mininet.link import Link, TCLink,Intf

from subprocess import Popen, PIPE

from mininet.log import setLogLevel

import subprocess

if '__main__' == __name__:

setLogLevel('info')

net = Mininet(link=TCLink)

ret = subprocess.run(

["sysctl","-w","net.ipv4.tcp_congestion_control=dctcp"],

capture_output=True,

text=True,

check=True

)

print("stdout:", ret.stdout.strip())

print("stderr:", ret.stderr.strip())

ret = subprocess.run(

["sysctl","-w","net.ipv4.tcp_ecn=1"],

capture_output=True,

text=True,

check=True

)

print("stdout:", ret.stdout.strip())

print("stderr:", ret.stderr.strip())

h1 = net.addHost('h1', hostname='h1')

h2 = net.addHost('h2', hostname='h2')

r1 = net.addHost('r1', hostname='r1')

h1.cmd("sysctl -w net.ipv4.tcp_ecn=1")

h2.cmd("sysctl -w net.ipv4.tcp_ecn=1")

r1.cmd("sysctl -w net.ipv4.tcp_ecn=1")

linkopt={'bw':10}

net.addLink(r1,h1,cls=TCLink, bw = 20, delay = '5ms',loss = 10, enable_ecn=True)

net.addLink(r1,h2,cls=TCLink, bw = 5, delay = '50ms',loss = 10, enable_ecn=True)

net.build()

r1.cmd("ifconfig r1-eth0 0")

r1.cmd("ifconfig r1-eth1 0")

h1.cmd("ifconfig h1-eth0 0")

h2.cmd("ifconfig h2-eth0 0")

r1.cmd("echo 1 > /proc/sys/net/ipv4/ip_forward")

r1.cmd("ifconfig r1-eth0 10.0.0.1 netmask 255.255.255.0")

r1.cmd("ifconfig r1-eth1 10.0.1.1 netmask 255.255.255.0")

r1.cmd("tc qdisc del dev r1-eth0 root")

r1.cmd("tc qdisc add dev r1-eth0 root fq_codel limit 10 ecn")

r1.cmd("tc qdisc del dev r1-eth1 root")

r1.cmd("tc qdisc add dev r1-eth1 root fq_codel limit 10 ecn")

h1.cmd("ifconfig h1-eth0 10.0.0.2 netmask 255.255.255.0")

h2.cmd("ifconfig h2-eth0 10.0.1.2 netmask 255.255.255.0")

h1.cmd("ip rule add from 10.0.0.2 table 1")

h1.cmd("ip route add 10.0.0.0/24 dev h1-eth0 scope link table 1")

h1.cmd("ip route add default via 10.0.0.1 dev h1-eth0 table 1")

h1.cmd("ip route add default scope global nexthop via 10.0.0.1 dev h1-eth0")

h2.cmd("ip rule add from 10.0.1.2 table 1")

h2.cmd("ip route add 10.0.1.0/24 dev h2-eth0 scope link table 1")

h2.cmd("ip route add default via 10.0.1.1 dev h2-eth0 table 1")

h2.cmd("ip route add default scope global nexthop via 10.0.1.1 dev h2-eth0")

CLI(net)

net.stop()