If you are using individual PSEs, then use the procedure below to export the application server's public-key certificate so that is available for import into the other servers' certificate lists.
Using the trust manager (transaction STRUST):
The SNC PSE's information appears in the PSE maintenance section.
The certificate's information appears in the certificate section.
The export dialog appears.
The application server's public-key certificate is located in the file system.
For each of the connections that you want to protect using SNC, import the application server's public-key certificate into the partner's certificate list and create credentials for that server's user. For more information, see Maintaining the Server's Certificate List Using SAPGENPSE.