DNS problem

[robinsmidsrod]

Yes, you have DNS available, but you're trying to do HTTPS on an IP-address. HTTPS expects the host in the URL to be a domain name, or else it can't validate that the certificate matches. So what it actually tries to pretend is a DNS hostname is the literal string "192.168.0.52", which it obviously is not. Configure a hostname for the server at 192.168.0.52 in your DNS and stick that name in your script instead of the IP. Obviously you must also make sure that the certificate you're using on the web server matches that name. See http://ipxe.org/crypto for more details on the HTTPS support.