I'm running 18.06.2 on the Linksys WRT1900ACS.
I recently set up radio0 interface (Marvell 88W8864 802.11nac Channel: 36 (5.180 GHz)) with WPA2 PSK (CCMP) and I have the strange problem that both computers and phones are able to join the WiFi network, but the router is not assigning IPv4 addresses to either computers or phones.
In LuCI, Network-Interfaces for the LAN settings page I have the "Ignore interface" checkbox left unchecked because I don't want to "Disable DHCP for this interface." But the router seems to be acting as if this checkbox was checked.
Under the Advanced Settings tab, the Dynamic DHCP checkbox is checked because I do want to "Dynamically allocate DHCP addresses for clients. If disabled, only clients having static leases will be served."
I've left the Force checkbox on that tab unchecked as there is only this DHCP server on the network.
In the IPv6 tab, I've disabled Router Advertisement-Service and DHCPv6-Service and NDP-Proxy but I disabled these after I encountered the problem with failure to assign IPv4 addresses when I noticed that IPv6 addresses are getting assigned to clients that join the WiFi network.
When I look at LuCI's Status->Overview page, in the "Active DHCPv6 Leases" section, I see two IPv6 addresses assigned to two computers (from the time period before I disabled the IPv6 server settings), and in the "Active DHCP Leases" section, I see "There are no active leases."
On the client, I note that when I manually assign an IPv4 address and netmask and router address in a computer that has joined the WiFi network associated with the radio0 interface, I do get normal LAN and WAN access on that computer. But I do want DHCP to assign IPv4 addresses.
I looked at One wireless interface connecting and then not assigning DHCP addresses to see if my problem was related, but I don't think it is related for two reasons: (1) my router is the Linksys WRT1900ACS (theirs was the WRT3200ACM) and (2) I seem to have only two interfaces (BGN and NAC) whereas they had three interfaces; plus, I'm using my NAC (5.180 GHz) interface and seeing this problem whereas the other post author reported that "This only happens on the 2.4GHz bgn interface".
Any ideas on what is causing my problem with my router not assigning IPv4 addresses to clients that join the WiFi network?
Thanks in advance.