Can establish outgoing connections through IPsec tunnel but can't establish incomming connections

  • Hi!

    Sorry if it's a newbie question. I have set up a pfsense 2.4.4_3 with a IPsec tunnel and a OpenVPN service following tutorials, without (I think) any special configuration. OpenVPN is working fine but something is wrong in the IPsec tunnel: I can create connections towards the other side of the tunnel but I cannot do it in the opposite direction, from the external network to the internal private network. I have stopped the firewall 'pfctl -d' with same results. I can't see any relevant error message in System Logs.

    Capturing network traffic while trying to create several connections from the other side of the tunnel towards the internal private network I realize that the only packet that is reaching the client is the first 'SYN+ACK' sent by the server. The other outgoing packages can be found in the IPsec interface of pfsense but they don't reach the client in the other side of the tunnel. So, the first incoming connection is established but it's no usable to send data and the last connection, new incoming connections are not established. Then if you wait a few more than a minute then something expires and it happens again that the first 'SYN+ACK' do reaches the client, but no more packets. It's such a strange behavior.

    Any help would be appreciated.
    Best regards,

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