Blocked TCP ACK when connected with VPN (PPTP)

  • Hi,
    I see there are already some topics simular to mine. But due to the reason that this is maybe related to VPN I´ve created a new topic.

    I have the following network structure.
    dyn. WAN address on the PFSENSE
    LAN IP address of PFSENSE is  (LAN Subnet is
    PPTP VPN configuration will provide IP addresses for remote users from on.

    When I connect via PPTP I see in the firewall log that ACKN are blocked. (see attachment)
    As you can see in the firewall configuration of LAN everything is allowed.

    Any hints?


  • Rebel Alliance Developer Netgate

    Seeing a blocked ACK packet means the firewall is only seeing the return traffic, and not the traffic coming in. From that, it sounds like you may have some asymmetric routing happening that is causing the firewall to only see half the traffic.

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