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    Poor performace with Openvpn

    Scheduled Pinned Locked Moved OpenVPN
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    • stephenw10S Offline
      stephenw10 Netgate Administrator
      last edited by

      The 'Cwnd' column in iperf. It only shows it at the end sending so you need to check both.

      But you can see it's much larger outside the tunnel. You might need mss-fix to prevent fragmentation.

      Steve

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      • T Offline
        trumee
        last edited by trumee

        I followed this article to get the value for mssfix.

        $ping -M do -s 1470  SiteB
        PING SiteB 1470(1498) bytes of data.
        ping: local error: message too long, mtu=1492
        ping: local error: message too long, mtu=1492
        ping: local error: message too long, mtu=1492
        
        $ ping -M do -s 1464  -c 1 SiteB
        PING SiteB 1464(1492) bytes of data.
        1468 bytes from SiteB: icmp_seq=1 ttl=55 time=51.5 ms
        
        

        According to the article mssfix = mtu-40, so i used mssfix 1424 in the client config of SiteB. Further following this article, i subtracted 28 from the MTU and set link-mtu to 1436.

        So finally the config looks so,

        $cat /var/etc/openvpn/client2.conf
        dev ovpnc2
        verb 1
        dev-type tun
        dev-node /dev/tun2
        writepid /var/run/openvpn_client2.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 myip
        engine cryptodev
        tls-client
        client
        lport 0
        management /var/etc/openvpn/client2.sock unix
        remote SiteA 1194
        ifconfig 10.8.9.2 10.8.9.1
        auth-user-pass /var/etc/openvpn/client2.up
        auth-retry nointeract
        route 172.16.1.0 255.255.255.0
        route 172.16.9.0 255.255.255.0
        ca /var/etc/openvpn/client2.ca 
        cert /var/etc/openvpn/client2.cert 
        key /var/etc/openvpn/client2.key 
        tls-auth /var/etc/openvpn/client2.tls-auth 1
        ncp-ciphers AES-128-GCM:AES-256-GCM
        compress lz4-v2
        resolv-retry infinite
        topology subnet
        mssfix 1424
        link-mtu 1436
        

        With the above config i get following result in the reverse.

        $iperf3 -s
        Accepted connection from 172.16.9.21, port 35516
        [  5] local 192.168.1.111 port 5201 connected to 172.16.9.21 port 35518
        [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
        [  5]   0.00-1.00   sec   416 KBytes  3.41 Mbits/sec    0   30.9 KBytes       
        [  5]   1.00-2.00   sec  1.09 MBytes  9.16 Mbits/sec    0   78.6 KBytes       
        [  5]   2.00-3.00   sec  2.71 MBytes  22.8 Mbits/sec    0    201 KBytes       
        [  5]   3.00-4.00   sec  2.26 MBytes  19.0 Mbits/sec   20    112 KBytes       
        [  5]   4.00-5.00   sec  2.22 MBytes  18.6 Mbits/sec    0    121 KBytes       
        [  5]   5.00-6.00   sec  2.47 MBytes  20.7 Mbits/sec    0    135 KBytes       
        [  5]   6.00-7.00   sec  2.71 MBytes  22.7 Mbits/sec    0    149 KBytes       
        [  5]   7.00-8.00   sec  2.96 MBytes  24.8 Mbits/sec    0    162 KBytes       
        [  5]   8.00-9.00   sec  3.21 MBytes  26.9 Mbits/sec    0    175 KBytes       
        [  5]   9.00-10.00  sec  3.45 MBytes  29.0 Mbits/sec    0    189 KBytes       
        [  5]  10.00-10.05  sec   252 KBytes  41.2 Mbits/sec    0    189 KBytes       
        - - - - - - - - - - - - - - - - - - - - - - - - -
        [ ID] Interval           Transfer     Bitrate         Retr
        [  5]   0.00-10.05  sec  23.7 MBytes  19.8 Mbits/sec   20             sender
        -----------------------------------------------------------
        Server listening on 5201
        -----------------------------------------------------------
        

        So it hasnt improved the speed.

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        • stephenw10S Offline
          stephenw10 Netgate Administrator
          last edited by

          Hmm the window size is tiny though.

          I would run a packet capture of the iperf traffic over the tunnel and see what's happening there, is it still fragmenting.

          You can test it by setting the window and mss size in the iperf client.

          Steve

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          • P Offline
            pete35
            last edited by

            Hmmm, even the performance isnt symetrical, it is way to low.

            What are the crypto settings of this tunnel ? Is AESNI used? Did you check the tunnel IPv4 settings? What version of Pfsense is that on both sites? Are this the standard Nic of the boards? With the newer OVPN versions, there are some additional buffer Settings , did you use that? Anything other on that connection?

            <a href="https://carsonlam.ca">bintang88</a>
            <a href="https://carsonlam.ca">slot88</a>

            P 1 Reply Last reply Reply Quote 0
            • P Offline
              pete35 @pete35
              last edited by

              What is the value of cryptographic settings in Advanced- Miscellaneous? It should be "aes-ni" on both sites... and inside the tunnel configuration ... "none" ...

              <a href="https://carsonlam.ca">bintang88</a>
              <a href="https://carsonlam.ca">slot88</a>

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              • stephenw10S Offline
                stephenw10 Netgate Administrator
                last edited by

                Even without AES-NI it should be faster with that hardware.

                It is possible to incorrectly use the crypto framework which can actually reduce throughput. OpenSSL will use AES-NI if the CPU has it.

                But even with that 30Mbps is far lower than expected.

                Steve

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                • T Offline
                  trumee @pete35
                  last edited by

                  @pete35 said in Poor performace with Openvpn:

                  What is the value of cryptographic settings in Advanced- Miscellaneous? It should be "aes-ni" on both sites... and inside the tunnel configuration ... "none" ...

                  These are the crypto settings on both sides, https://imgur.com/a/Qzar59q

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                  • P Offline
                    pete35 @trumee
                    last edited by

                    @trumee

                    pls remove all configurations, where "cryptodev" is included and set it to aesni only.

                    <a href="https://carsonlam.ca">bintang88</a>
                    <a href="https://carsonlam.ca">slot88</a>

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                    • T Offline
                      trumee @pete35
                      last edited by trumee

                      @pete35 said in Poor performace with Openvpn:

                      @trumee

                      pls remove all configurations, where "cryptodev" is included and set it to aesni only.

                      I have enabled AESNI in Advanced-Miscellaneous. In the tunnel configuration, should the 'Hardware Crypto' be set to 'No Hardware Crypto Acceleration'?

                      alt text

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                      • RicoR Offline
                        Rico LAYER 8 Rebel Alliance
                        last edited by

                        Yes.

                        -Rico

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                        • stephenw10S Offline
                          stephenw10 Netgate Administrator
                          last edited by

                          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

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                          • T Offline
                            trumee
                            last edited by

                            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
                            -----------------------------------------------------------
                            
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                            • RicoR Offline
                              Rico LAYER 8 Rebel Alliance
                              last edited by

                              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

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                              • RicoR Offline
                                Rico LAYER 8 Rebel Alliance
                                last edited by

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

                                -Rico

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                                • T Offline
                                  trumee @Rico
                                  last edited by 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
                                  
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                                  • T Offline
                                    trumee @Rico
                                    last edited by

                                    @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.
                                    
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                                    • stephenw10S Offline
                                      stephenw10 Netgate Administrator
                                      last edited by

                                      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

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                                      • T Offline
                                        trumee @stephenw10
                                        last edited by

                                        @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?

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                                        • stephenw10S Offline
                                          stephenw10 Netgate Administrator
                                          last edited by

                                          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

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                                          • T Offline
                                            trumee @stephenw10
                                            last edited by

                                            @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?
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