I am trying to make a callout to a SAP webservice that is connected through a VPN. It is not accessible and getting IO Exception Unauthorized end point error.

System.CalloutException: IO Exception: Unauthorized end point

The webservice is also available through a public internet IP, but for the security reasons the client wants to access the webservice from salesforce through a VPN connection. Is that possible? Any suggestions please?


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    Your Internal network team will have to configure the Ip addresses which salesforce provides and also add the web service url in the remote site settings in salesforce. help.salesforce.com/apex/… Jun 24, 2014 at 21:21

1 Answer 1


Your service has to be accessible from the public Internet, because you can't access VPN from salesforce.

That said, there are many ways to secure your services from unintentional or malicious outside transactions. The organization I work for uses a multifaceted approach that includes many layers of protection.


Don't tunnel directly from an external IP into your service (eg DMZ, port forwarding). Instead, consider a proxy server that requires authentication.


You can use two way SSL and/or some authentication mechanism, such OAuth or tokens of other types. This will harden your service against access.

Client IP Filtering

Salesforce maintains a list of their IP addresses. You can configure your proxy to only allow transactions from this list of approved IP addresses.

Logging and IDS

Use a logging system, and train an Intrusion Detection System to detect unusual patterns. This will help identify and mitigate attacks. This is important in the event that someone does slip by all the other protection layers.

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