This issue also applies (though not explicitly stated in the article) for the Linchpin Mobile on-Site Gateway. Simply replace the //SEIBERT/MEDIA Linchpin Mobile Cloud Gateway's IP address by your internal Gateway's IP.
The Confluence instance running behind a firewall with no access to the public internet cannot connect to the Linchpin Mobile Cloud Gateway hosted by //SEIBERT/MEDIA. When establishing a connection via the Confluence admin panel there's a popup displaying the following error message.
The Linchpin Mobile Confluence App needs to connect to the Linchpin Mobile Cloud Gateway hosted by //SEIBERT/MEDIA via the internet.
If your firewall is blocking all outgoing connections the Linchpin Mobile Confluence App isn't able to communicate with the Gateway.
To resolve this issue add a whitelist entry to your firewall to accept outgoing HTTPS connections on port 443 to the IP 18.104.22.168 and the URLs https://firescope.seibert-media.net and https://firescope-1.seibert-media.net (//SEIBERT/MEDIA hosted Linchpin Mobile Gateway). Please also make sure that the Confluence system is able to do a DNS-resolution for the hosts firescope.seibert-media.net and firescope-1.seibert-media.net
Please be aware that this IP address can change any time in the future. In order to get a notification about upcoming IP changes please contact us.
Looking for an alternative to port whitelisting?
If you do not want to put a port whitelisting in place or if whitelisting is restricted by your company's security guidelines get more information on our on-site Linchpin Mobile Gateway that can be hosted within your company's infrastructure.