OpenVPN Client-to-Site is very slow



  • hello dear,

    i fight against this problem for a few days…
    Here are some informations about my config:

    • pfSense running on an ESX 5.5 --> Version 2.2.5 (updated today, before 2.2.4) (AMD 64)
    • Hardware: 4GB Ram, Dual-Core, i think this is enough to handle 2-3 clients
    • WAN Connection: (Download >100mbit, Upload >70mbit)
    • OpenVPN Client-to-Site connections are authenticate over LDAP (Active Directory Domaincontroller)
    • Safety: AES 256bit CBC

    Everything works fine but the bandwith is very slow. More than 3mbit is not possible (but over 70mbit upload is possible)
    I try the following things to increase the bandwith but it does not help:

    • Decrease the safety to AES 128 CBC (There was only a lower CPU load)
    • a lot of different openvpn clients
    • changed the following settings in the advanced field: tun-mtu 1500; mssfix 1400;
    • all possible settings for lzo compression
    • Downgrade the pfsense on the following versions: 2.2.3, 2.2.2, 2.2.1, 2.2 and 2.15
    • net.inet.ip.fastforwarding switch to value 1

    All this settings do not solve my bandwith limitation.

    Does anyone have some ideas?

    Thansk in advance


  • LAYER 8 Netgate

    What kind of connection are the clients using?


  • LAYER 8 Global Moderator

    "Everything works fine but the bandwith is very slow. More than 3mbit is not possible"

    How are you testing this bandwidth?  A file copy via smb?  SMB over a wan is going to blow.. What is the latency these clients have??  20ms?  Higher?

    I run pfsense on esxi, and I vpn in all the time.. Now my upload is limited to 12mpbs at the pfsense end.. But I know for sure I get better than 3…



  • I tested with ipferf. But now, from another wan connection i get "normal" performance. i think there was a issue with the other wan connection i used for my vpn.
    thanks a lot for the fast reply :)
    my configuration seems to be okay!



  • because i found this topic already open will update with the same issue i have. The openvpn connection is verry slow. When i try to copy something it gets a max of 50kb/s !!!

    I have attached the connections for both client(speedtest) and pfsense-openvpn server(console).
    On the Openvpn side i use:

    • DH Parameter length (bits) - 2048
    • Encryption Algorithm - AES-256-CBC
    • Auth digest algorithm - sha256
    • Hardware Crypto - Intel RDRAND engine

    Should i need to lower those?

    Thank you

    ![Screen Shot 2016-10-02 at 13.41.26.png](/public/imported_attachments/1/Screen Shot 2016-10-02 at 13.41.26.png)
    ![Screen Shot 2016-10-02 at 13.41.26.png_thumb](/public/imported_attachments/1/Screen Shot 2016-10-02 at 13.41.26.png_thumb)


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