Why did I get result code -1?

This error can be caused by:

• The firewall or other network software or hardware is blocking inbound or outbound TCP (Transmission Control Protocol) traffic on port 443
• The network uses a "non-transparent" proxy to handle requests without specifying the parameters
• An incorrect or deprecated endpoint is being used
• Your current integration does not comply with the PayPal Security Guidelines

Blocked TCP traffic
Verify that port 443 is open for both inbound and outbound TCP traffic. To do this, telnet into your server using either the server name or the IP address on port 443 (for example telnet 123.456.123.012 443). A blinking cursor indicates an open port. A "failed to connect" message indicates a closed port.

Network Proxy Use
If you use a proxy, make sure that the parameters include the Payflow Pro client needs. Specifically, IP address (required), port (default=443), proxy logon, and proxy password. See the Payflow Gateway Developer Guide for specific information regarding proxy server settings.

Note: To check for connectivity, run a cURL command or an openssl command. If you use a UNIX environment or have an open-source tool such as Cygwin, issue the following commands to check connectivity.

• Run command line using cURL:
  curl -d -v https://pilot-payflowpro.paypal.com
• Run command line (OpenSSL):
  openssl s_client -connect payflowlink.paypal.com:443

PayPal Endpoints
Verify that you are using the correct endpoint.