We can't enable the incoming authentication because Atlasian Bamboo is not reachable.

[Niels Joergensen]

When accessing "Bamboo" from "JIRA" we get the above information

[Daniel Ebers]

Hi Niels,

while the error message is a bit generic, indeed I'd recommend you to check if both applications are able to communicate with each other. Basically a plain test via telnet and/or ping could be a first step into troubleshooting.

Additionally I will provide you the link for the setup of application links between Jira and Bamboo:

https://confluence.atlassian.com/bamboo/integrating-bamboo-with-jira-applications-289276945.html

In case you would provide some more details about the setup somebody from Community might be able to catch up easier.

Cheers,
Daniel