Poor performace with Openvpn

Rico

Yes.

-Rico

stephenw10

Set it to no-hardware crypto there.

It will be interesting to see if that makes any measurable difference. The speeds you're seeing seem to be less than anything I would expect to be affected by that.

Steve

trumee

I set it to 'No Hardware Crypto'. It did not make a difference.

[  5] local 192.168.1.111 port 5201 connected to 192.16.9.21 port 33160
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  1.74 MBytes  14.6 Mbits/sec    2   92.3 KBytes       
[  5]   1.00-2.00   sec  1.87 MBytes  15.7 Mbits/sec    0    109 KBytes       
[  5]   2.00-3.00   sec  2.05 MBytes  17.2 Mbits/sec    0    117 KBytes       
[  5]   3.00-4.00   sec  2.24 MBytes  18.8 Mbits/sec    0    125 KBytes       
[  5]   4.00-5.00   sec  2.43 MBytes  20.3 Mbits/sec    0    138 KBytes       
[  5]   5.00-6.00   sec  2.30 MBytes  19.3 Mbits/sec    3    110 KBytes       
[  5]   6.00-7.00   sec  2.24 MBytes  18.8 Mbits/sec    0    131 KBytes       
[  5]   7.00-8.00   sec  1.99 MBytes  16.7 Mbits/sec   12   71.5 KBytes       
[  5]   8.00-9.00   sec  1.49 MBytes  12.5 Mbits/sec    0   81.9 KBytes       
[  5]   9.00-10.00  sec  1.49 MBytes  12.5 Mbits/sec    0   94.9 KBytes       
[  5]  10.00-10.05  sec   191 KBytes  29.6 Mbits/sec    0   96.2 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.05  sec  20.0 MBytes  16.7 Mbits/sec   17             sender
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

Rico

Please share all your OpenVPN settings.
What is your Encryption Algorithm?
With GCM I have seen OpenVPN traffic beyond 400 MBit/s
My SG-5100 can easy do ~250 MBit/s

-Rico

Rico

For testing...could you set the Encryption Algorithm to None? Just to rule this out...

-Rico

trumee

@Rico I am using 'cipher AES-256-CBC', 'auth SHA256' and ncp-ciphers 'AES-256-GCM:AES-128-GCM'. The server side VPN config is the following and the client side config is posted above.

$less /var/etc/openvpn/server1.conf
dev ovpns1
verb 1
dev-type tun
dev-node /dev/tun1
writepid /var/run/openvpn_server1.pid
#user nobody
#group nobody
script-security 3
daemon
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
proto udp4
cipher AES-256-CBC
auth SHA256
up /usr/local/sbin/ovpn-linkup
down /usr/local/sbin/ovpn-linkdown
local 127.0.0.1
tls-server
server 10.8.9.0 255.255.255.0
client-config-dir /var/etc/openvpn-csc/server1
ifconfig 10.8.9.1 10.8.9.2
tls-verify "/usr/local/sbin/ovpn_auth_verify tls 'VoipVPNServer' 1"
lport 1194
management /var/etc/openvpn/server1.sock unix
route 192.168.0.0 255.255.255.0
route 192.168.1.0 255.255.255.0
route 192.168.2.0 255.255.255.0
route 192.168.5.0 255.255.255.0
route 192.168.6.0 255.255.255.0
route 192.168.10.0 255.255.255.0
route 192.168.18.0 255.255.255.0
route 192.168.40.0 255.255.255.0
route 192.168.50.0 255.255.255.0
ca /var/etc/openvpn/server1.ca 
cert /var/etc/openvpn/server1.cert 
key /var/etc/openvpn/server1.key 
dh /etc/dh-parameters.2048
crl-verify /var/etc/openvpn/server1.crl-verify 
tls-auth /var/etc/openvpn/server1.tls-auth 0
ncp-ciphers AES-256-GCM:AES-128-GCM
compress lz4-v2
persist-remote-ip
float
topology subnet

trumee

@Rico said in Poor performace with Openvpn:

For testing...could you set the Encryption Algorithm to None? Just to rule this out...

-Rico

There is no change to the result,

$ iperf3 -c 192.168.1.111 -R
Connecting to host 192.168.1.111, port 5201
Reverse mode, remote host 192.168.1.111 is sending
[  5] local 172.16.9.21 port 33962 connected to 192.168.1.111 port 5201
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  1.21 MBytes  10.2 Mbits/sec                  
[  5]   1.00-2.00   sec  1.61 MBytes  13.5 Mbits/sec                  
[  5]   2.00-3.00   sec   905 KBytes  7.41 Mbits/sec                  
[  5]   3.00-4.00   sec  1.01 MBytes  8.48 Mbits/sec                  
[  5]   4.00-5.00   sec   538 KBytes  4.41 Mbits/sec                  
[  5]   5.00-6.00   sec   753 KBytes  6.17 Mbits/sec                  
[  5]   6.00-7.00   sec   987 KBytes  8.09 Mbits/sec                  
[  5]   7.00-8.00   sec  1.18 MBytes  9.88 Mbits/sec                  
[  5]   8.00-9.00   sec  1.43 MBytes  12.0 Mbits/sec                  
[  5]   9.00-10.00  sec  1.65 MBytes  13.9 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.05  sec  11.6 MBytes  9.67 Mbits/sec  150             sender
[  5]   0.00-10.00  sec  11.2 MBytes  9.40 Mbits/sec                  receiver

iperf Done.

stephenw10

Did you disable NCP? Otherwise it will still be negotiating those.

But as I said this looks like some sort of mtu/fragmenting issue. Run a packet capture and see what's happening.

Steve

trumee

@stephenw10 said in Poor performace with Openvpn:

Did you disable NCP? Otherwise it will still be negotiating those.

But as I said this looks like some sort of mtu/fragmenting issue. Run a packet capture and see what's happening.

Steve

I have done packet capture. What should i be looking for in wireshark?

stephenw10

Fragmented packets is the first thing I would be looking for. Then what size the large fragments are.

Otherwise check the initial TCP transactions for the window size etc. Do you see retranmissions or missing packet errors.

Steve

trumee

@stephenw10 said in Poor performace with Openvpn:

Fragmented packets is the first thing I would be looking for. Then what size the large fragments are.

Otherwise check the initial TCP transactions for the window size etc. Do you see retranmissions or missing packet errors.

Steve

I captured VPN interface and opened the capture in wireshark. I dont see any fragmented packet in the Info column.

Should I capture the WAN interface instead of the VPN interface?
Is there any wireshark tutorial which shows how to identify whether fragmentation is occuring?

stephenw10

I'm not aware of any specific tutorial for that, there are many though.

Packet fragmentation is not difficult to spot though even just from the pfSense interface.

11:54:54.373954 IP 172.21.16.35 > 172.21.16.5: ICMP echo request, id 39018, seq 0, length 1480
11:54:54.373963 IP 172.21.16.35 > 172.21.16.5: ip-proto-1
11:54:55.374734 IP 172.21.16.35 > 172.21.16.5: ICMP echo request, id 39018, seq 1, length 1480
11:54:55.374743 IP 172.21.16.35 > 172.21.16.5: ip-proto-1
11:54:56.375739 IP 172.21.16.35 > 172.21.16.5: ICMP echo request, id 39018, seq 2, length 1480
11:54:56.375749 IP 172.21.16.35 > 172.21.16.5: ip-proto-1

Pinging size 2000 byte packets, each full size packet is followed by a fragment to make up the full packet.

In that particular case there is a switch I have that doesn't pass packet fragments.

Try looking at the OpenVPN traffic on the WAN also. If that is fragmented it will kill performance.

Steve

trumee

For comparison sake i setup wireguard between the two networks. Wireguard starts with an MTU of 1420, and it reaches almost the line-speed in both forward and reverse directions.

# wg-quick up wg0  
[#] ip link add wg0 type wireguard
[#] wg setconf wg0 /dev/fd/63
[#] ip -4 address add 10.0.0.2/32 dev wg0
[#] ip link set mtu 1420 up dev wg0
[#] ip -4 route add 10.0.0.0/24 dev wg0

root@wireguard:/etc/wireguard# iperf3 -c 10.0.0.1 
Connecting to host 10.0.0.1, port 5201
[  4] local 10.0.0.2 port 34842 connected to 10.0.0.1 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  14.8 MBytes   124 Mbits/sec    0   1.74 MBytes       
[  4]   1.00-2.00   sec  16.8 MBytes   141 Mbits/sec    0   2.58 MBytes       
[  4]   2.00-3.00   sec  17.0 MBytes   142 Mbits/sec    3   2.96 MBytes       
[  4]   3.00-4.00   sec  16.0 MBytes   134 Mbits/sec    1   2.07 MBytes       
[  4]   4.00-5.00   sec  16.7 MBytes   140 Mbits/sec    1   1.52 MBytes       
[  4]   5.00-6.00   sec  17.0 MBytes   142 Mbits/sec    0   1.62 MBytes       
[  4]   6.00-7.00   sec  16.9 MBytes   142 Mbits/sec    0   1.70 MBytes       
[  4]   7.00-8.00   sec  16.8 MBytes   141 Mbits/sec    0   1.75 MBytes       
[  4]   8.00-9.00   sec  16.9 MBytes   142 Mbits/sec    0   1.79 MBytes       
[  4]   9.00-10.00  sec  17.0 MBytes   142 Mbits/sec    2    920 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   166 MBytes   139 Mbits/sec    7             sender
[  4]   0.00-10.00  sec   163 MBytes   137 Mbits/sec                  receiver

iperf Done.
root@wireguard:/etc/wireguard# iperf3 -c 10.0.0.1 -R
Connecting to host 10.0.0.1, port 5201
Reverse mode, remote host 10.0.0.1 is sending
[  4] local 10.0.0.2 port 35042 connected to 10.0.0.1 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  13.0 MBytes   109 Mbits/sec                  
[  4]   1.00-2.00   sec  16.9 MBytes   141 Mbits/sec                  
[  4]   2.00-3.00   sec  16.9 MBytes   142 Mbits/sec                  
[  4]   3.00-4.00   sec  16.9 MBytes   142 Mbits/sec                  
[  4]   4.00-5.00   sec  16.9 MBytes   142 Mbits/sec                  
[  4]   5.00-6.00   sec  16.9 MBytes   142 Mbits/sec                  
[  4]   6.00-7.00   sec  16.9 MBytes   142 Mbits/sec                  
[  4]   7.00-8.00   sec  16.9 MBytes   141 Mbits/sec                  
[  4]   8.00-9.00   sec  16.9 MBytes   142 Mbits/sec                  
[  4]   9.00-10.00  sec  16.9 MBytes   142 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   168 MBytes   141 Mbits/sec    3             sender
[  4]   0.00-10.00  sec   168 MBytes   141 Mbits/sec                  receiver