This article concerns static-IP clients. If you’re seeing missing hostnames on a DHCP client, that’s a separate issue — open a support ticket.
What’s going on
The hostname column on Portal › Devices can be unreliable
for clients with static IPs. The gateway can only fill in that
field when the client volunteers its name to the gateway — for
example via a DNS update or a DHCP request that includes the
hostname option. Many static-IP clients never have any
transaction with the gateway that carries a hostname, so the
field stays blank.
The same applies when there’s a third-party DHCP server on-site — the gateway never sees the DHCP exchange, so it can’t pick up the names.
How to recognise affected clients
The clearest signal is the IP address column. If it reads non-DHCP, that client took its IP from somewhere other than the gateway, and is likely to have no name displayed for the same reason — the gateway never received a DHCP request from it. The gateway shows whatever other identifying information it can gather (MAC address, traffic patterns), but without a hostname to attach to.
Edge case: DHCP without a hostname
Occasionally a client does get a DHCP lease from the gateway but omits its hostname in the request. Those show up as “no name” too, unless the gateway happened to pick up the name by another method. It’s uncommon, but worth knowing about when a device is unexpectedly anonymous despite being on the Uplevel DHCP pool.