My Huawei HG533 router does not accurately report LAN-side connected devices.
There are two methods of listing LAN devices:
Status > LAN > Ethernet and Basic > LAN > Ethernet
These two lists seem to agree with each other but not always with what's actually connected. Devices which have disconnected are sometimes still shown and newly connected devices sometimes don't show up.
Today, whilst diagnosing a printer problem I saw the printer in the list with its DHCP allocated address of 192.168.1.18. Sometime after giving the printer a fixed IP address of 192.168.1.3, the router still showed it as 192.168.1.18, even though I was able to connect to the printer's internal web server on 192.168.1.3. After rebooting the router, the printer disappeared from the list.
As an experiment, I set a short (2 min) lease time on the DHCP server in the router and then set another device to a static address. Again the device still showed with the old IP address. Strangely, the previously displayed hostname reverted to a MAC address. When the lease expired, the device still showed in the table but with a status of "Lease achieved".
It would appear from this limited experiment that the device table actually shows valid and previous DHCP leases - not connected devices. However, I'm certain that at other times there have been DHCP enabled devices which were connected and communicating and yet not in the list.
Has anyone else seen similar results?