OpenVpn connection very slow

[AZ8]

I have a local OpenVPN server on Banan Pi M1, with latest armbian. I tried to replace with OrangePi3 but current results is disappointing

 

iperf3 results on Banana Pi M1 OpenVPN  server

 

Connecting to host bouygues.iperf.fr, port 5201
[  4] local 10.8.0.4 port 46250 connected to 89.84.1.222 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  1.69 MBytes  14.1 Mbits/sec                 
[  4]   1.00-2.00   sec  1.81 MBytes  15.1 Mbits/sec                 
[  4]   2.00-3.00   sec  2.43 MBytes  20.4 Mbits/sec                 
[  4]   3.00-4.00   sec   681 KBytes  5.58 Mbits/sec                 
[  4]   4.00-5.00   sec  1.99 MBytes  16.7 Mbits/sec                 
[  4]   5.00-6.00   sec  1.33 MBytes  11.2 Mbits/sec                 
[  4]   6.00-7.00   sec  1.55 MBytes  13.0 Mbits/sec                 
[  4]   7.00-8.00   sec  1.62 MBytes  13.6 Mbits/sec                 
[  4]   8.00-9.00   sec  1.33 MBytes  11.2 Mbits/sec                 
[  4]   9.00-10.00  sec  1.76 MBytes  14.8 Mbits/sec                 
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  16.2 MBytes  13.6 Mbits/sec                  sender
[  4]   0.00-10.00  sec  15.7 MBytes  13.2 Mbits/sec                  receiver
 

iperf3 results on Orange Pi 3 OpenVPN server

 

Connecting to host bouygues.iperf.fr, port 5201
[  4] local 10.8.1.4 port 41583 connected to 89.84.1.222 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec   621 KBytes  5.09 Mbits/sec                 
[  4]   1.00-2.00   sec   868 KBytes  7.11 Mbits/sec                 
[  4]   2.00-3.00   sec  1.18 MBytes  9.89 Mbits/sec                 
[  4]   3.00-4.00   sec  1.16 MBytes  9.75 Mbits/sec                 
[  4]   4.00-5.00   sec  1.02 MBytes  8.53 Mbits/sec                 
[  4]   5.00-6.00   sec   966 KBytes  7.92 Mbits/sec                 
[  4]   6.00-7.00   sec   726 KBytes  5.95 Mbits/sec                 
[  4]   7.00-8.00   sec   676 KBytes  5.54 Mbits/sec                 
[  4]   8.00-9.00   sec  2.58 MBytes  21.7 Mbits/sec                 
[  4]   9.00-10.00  sec  4.78 MBytes  40.1 Mbits/sec                 
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  14.5 MBytes  12.2 Mbits/sec                  sender
[  4]   0.00-10.00  sec  14.0 MBytes  11.7 Mbits/sec                  receiver

 

As you can see, connection via OPi3 is slower, but more than that, it is unstabe and fluctuating from 5-8 MBit/s to 40 MBit/s

 

What can I tune to improve openvpn connectivity?
 

[dolphs]

not sure on which kernel you are, but these kernel settings should give a boost:

put a .conf-file in " /etc/sysctl.d " and reboot. 

 

1/
net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr

2/
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216

net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 87380 16777216

3/ optional
net.ipv4.tcp_fastopen = 3
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_slow_start_after_idle = 0
net.ipv4.tcp_timestamps = 0

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.eth0.disable_ipv6 = 1

 

and certainly how looks your " server.conf ", eg some interesting settings .

Please mind cipher in this case, I picked AES-128-CBC

proto udp4
txqueuelen 1000
topology subnet

#Set socket buffersize following for UDP recommended, also push to client
sndbuf 393216
rcvbuf 393216
push "sndbuf 393216"
push "rcvbuf 393216"

float           #Allow remote IP to change but keep authentication in place
comp-lzo no     #No need for streaming
fast-io         #Optimize I/O writes

cipher AES-128-CBC
ncp-disable
auth SHA256
auth-nocache