We have following configuration:
jenkins/manage plugins/advanced proxy settings has proxy, but Jira is local to the network.
So we installed plugin, restarted jenkins, added proxy exception for Jira host.
Test button in config UI showed us that everything is connecting.
tcpdump showed us that request going directly to local jira.
Problem is that actual groovy code attempting to connect to proxy instead.
So we in sort of inconsistent state there test button in configuration says everything is ok, but in reality plugin seems to be caching startup setting.
We restarted jenkins and it started to respect noproxy setting.
So believe is that implementation of proxy configuration only picks it up on startup.
It would be nice to pick up current settings, but that is too complicated would be nice to at least have comment in the option description that it is only applied on restart.