In our environment we would like to use master access control, which we have running on an internal domain name. In our environment, in order to access external sites our traffic must go through a proxy. We have the proxy configured in Jenkins, which includes any internal address on the no proxy list, and the plugin configured to use the Jenkins proxy. What we have found is that when the access control url is an internal domain and therefore matches the no proxy list, that the plugin does not proxy any connections, even for the external domains we need proxied. I tracked this down to this check in the plugin: https://github.com/jenkinsci/checkmarx-plugin/blob/de6842b2b22d3ef28ec003873308837c437f83d0/src/main/java/com/checkmarx/jenkins/CxScanBuilder.java#L2761