Hostnames, URLs and the complete server endpoint

A server URL combines scheme, host, optional port and resource path, while hostname resolution and relative-reference rules determine distinct later selections.

A hostname is one component of a server URL. Copying only the name can discard information the client needs to reach the intended service.

Take this original endpoint:

https://media.example.net:45000/emby/
Component Value Role
Scheme https Requests the HTTPS application scheme
Host media.example.net Name used to select/resolve the endpoint
Explicit port 45000 Destination service port
Path /emby/ Resource/base location at that service

The endpoint is an invented example. DNS resolves the hostname’s relevant records; it does not normally replace all the other URL components.

Omitted ports have scheme defaults

Without an explicit port, HTTP uses its default 80 and HTTPS its default 443. Removing :45000 therefore changes the requested destination service in this example.

An Emby listener on a customized port does not become available at the scheme default merely because the client uses a familiar hostname.

Likewise, writing an https scheme does not make a plaintext listener perform TLS. Scheme and service behavior have to agree.

IPv6 address literals need brackets

Compare the original literal form:

https://[2001:db8:50::20]:8920/emby/

The brackets distinguish the IPv6 address’s internal colons from the separator before port 8920. The value uses the IPv6 documentation prefix.

A limited-scope IPv6 address can additionally need a requesting-interface context. Current RFC 9844 describes that user-interface problem; implementation support must be checked separately from an ordinary globally scoped bracketed literal.

Relative references use the current base

Use a base URL of https://media.example.net/emby/:

Reference Resolved URL path
login /emby/login
/login /login
../login /login

The leading slash starts from the origin root. It does not retain the application’s /emby prefix.

A reverse proxy can forward the initial page successfully and still expose broken later navigation if generated links, redirects or resource URLs disagree about the public base path.

Reverse proxies follows both sides of that relationship.

Name conventions carry resolution context

A .local name has multicast-DNS semantics in supporting clients. The home.arpa domain is specified for local home-network naming. An ordinary external domain uses its configured DNS arrangement.

These conventions do not guarantee that every TV app resolves names through the same operating-system path.

See Also

References