No connection could be made because the target machine actively refused it when using VPN?

Question

I have a couple users logging into work through VPN and an API that they were able to access before normally is being blocked with the following error:

Type: System.Net.Sockets.SocketException Target Site: Void InternalEndConnect(System.IAsyncResult) Message: No connection could be made because the target machine actively refused it

It is not a firewall issue because users were able to access this in our network, and the API is up and running. Could it be the VPN connection blocking it somehow, blocking the 443 port the API uses? We are using SonicWall NetExtender

You may have an existing connection partially open. So first check from cmd.exe > Netstat -a which will give status of connection. Are you using IP or computer name. If DCHP is enabled the IP address changes periodically while name always is the same. So users should always use the computer name and not the IP. — jdweng

Jason Owens Jason Owens · Accepted Answer · 2020-04-02T15:25:52

If you can log into the Sonicwall, go to NATS and see if anything is using that port, 443.

If you're accessing it within the network/office without issue, that's likely because you're never traversing the Firewall because you're on LAN to LAN traffic.

Verify you can ping the device from the firewall as well.

If you can ping it from the firewall, and you can see there is no NATs in use, verify 443 isn't in use by the management port also.

Lastly, verify which Mobile VPN you're using and their client (IPSEC or SSLVPN), NetExtender, Mobile Connect, Global VPN Client. I think SSL VPN could be setup using port 443.

No connection could be made because the target machine actively refused it when using VPN?

1 Answers