A URL can contain a literal IPv6 address. The format is standardized in RFC 2732. They look like this: http://[2610:8:6800:1::7]/

The Confluence editor does not properly parse addresses like this (presumably it is getting confused over the brackets in the URL).

If you enter the URL directly does not work. E.g. www.et-test.psu.edu

I tried escaping the brackets in the URL - www.et-test.psu.edu. That also did not work.