This is just HTTP protocol. If you use port 80 for HTTP the port can be left off the URL, port 443 for HTTPS.
Note that if you’re running on Linux those ports are restricted, so you’ll likely want to front Nexus Repo with a reverse proxy so you don’t have to run it as root.
https://help.sonatype.com/display/NXRM3/Run+Behind+a+Reverse+Proxy