I can send API requests using curl or Postman, but when I use my existing integration the application fails with an exception that reads, "An existing connection was forcibly closed by the remote host."
- TLS 1, 1.1, 1.2
- 400 Error
- HTTP Request
Ensure you are using the correct TLS version by making an HTTP request to the following URL https://api.nexmo.com/tlsverification from your application. This end-point will return a 200 OK if the application correctly supports TLS v 1.2 and a 400 error if not.
It is possible that your application is using a deprecated TLS version when sending HTTPs requests to Vonage APIs. Note that legacy TLS version 1 and 1.1 were permanently disabled for all public endpoints as of 21 August 2018, due to serious security vulnerabilities in these protocols.