Add a note about Idp connectivity (#1329) (#1333)

Add a note to ensure the Neo4j server is able to connect to the identity
provider, as this is required for operation.

---------

Co-authored-by: Mark Dixon <[email protected]>
Co-authored-by: Phil Wright <[email protected]>
Co-authored-by: Reneta Popova <[email protected]>

Author: 4 people

modules/ROOT/pages/authentication-authorization/sso-integration.adoc

@@ -152,6 +152,11 @@ dbms.security.authentication_providers=oidc-newsso,oidc-oldsso,native
 dbms.security.authorization_providers=oidc-newsso,oidc-oldsso,native
 ----
 ======
+. Check connectivity.
+Neo4j needs to connect to the identity provider to discover settings and fetch public keys to verify tokens.
+Check firewall settings and security controls, and, if necessary, logs to ensure that the Neo4j server is able to connect to the identity provider using HTTPS.
+If a proxy is required, this can be https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/net/doc-files/net-properties.html#Proxies[configured] in the Java virtual machine using the configuration setting xref:configuration/configuration-settings.adoc#config_server.jvm.additional[server.jvm.additional].
+Proxies that require credentials are not supported.
 
 [[auth-sso-map-idp-roles]]
 == Map the Identity Provider Groups to the Neo4j Roles