Yes, it would be very weird for server addresses to have the service name as a subdomain. Like a common prefix of web servers to signify that it’s serving world wide web.
On a more serious note, this used to be fairly common for many protocols to ensure loaf balancing between different protocols - you’d have one server for www, one for ftp, and so on.
Also, from an administrative point of view, it’s more manageable when you can, for example, add an entire (sub)domain to the firewall rules.
I was thinking the same thing. Spanning tree is love. Spanning tree is life…when deployed correctly.
Alternatively I’m thinking noise, as I’ve seen that in 10gig connections a few times, which is why I prefer LC fiber where possible.