Client unable to contact discovery server via domain name, only IP address works

[iaamp]

Context:
Using Fast-DDS as part of ROS 2 on Ubuntu 22.04 with ROS 2 humble and Ubuntu 20.04 with ROS 2 foxy.

Observation:
When using a client config such as the typical super_client_configuration_file.xml to discover ROS 2 nodes, the server <address> field can only be specified as the IP address, not as the domain name. In case domain name is used, the superclient is unable to see any nodes respectively topics.

Expectation:
Domain name works the same as IP address. This would be in line with how it works (from my observation) in the server config. For the server, the fastdds discovery -x <profile>@/path/to/config.xml command will resolve the hostname of the server if specified in the ..<locator><udpv4><address> XML field of the server config.

A point for consideration: I would assume that it may create problems in case the server machine would report to a host <server domain name> with more than one IP address. However, within a domain network, a machine is often reachable only via one specific interface and as such, one specific IP address gets reported upon a host request.