Our company has a Linksys router flashed with OpenWrt, placed in a recessed structure where the signal is not very good. Therefore, we added a TP-Link router with many protruding antennas as an AP.
Previously, there was an issue where connecting other devices (such as a LoRa gateway or other Wi-Fi AP) to the remaining LAN ports on the Linksys caused the DHCP server in the local area network to change to other devices. Usually, unplugging the other devices resolved the issue.
Recently, this Linksys router stopped assigning IPs to LAN devices even without any other devices connected besides the TP-Link AP.
Rebooting and resetting did not help. Connecting directly to its LAN port with a computer via an Ethernet cable sometimes allows obtaining an IP, but it disappears after a while.
At one point, I thought the hardware was faulty.
However, it is definitely an issue with the DHCP capability.
I searched through the system for various DHCP-related settings, and found that this setting worked:
Location:
Interfaces > LAN > DHCP Server > Advanced Settings > Force, enable it, save and apply, and that’s it.