This is my situation:
Main router IP -> 192.168.1.1
This router it's the DHCP server and have active there WiFi 5Ghz.
On other rooms i have another router... this runs OpenWRT 19.07.3.
The Both router it's connected by LAN cable... this router have IP -> 192.168.1.254
I don't know if i have correctly disabled the DHCP but i thinks yes...... this router have active there WiFi 2.4GHz.
Now... the problems it's i can see all device correctly associated to this wi-fi but i can see the MAC Address but on hostname it's appears a strange value... somethings like a ipv6... for example one of this:
I don't have idea what's devices it's..... i can see your complete information only if i access to panel of main router and here i can see him MAC Address and the ip correctly assigned by DHCP.
Can I make this happen in both configuration panels ?
First make sure the dhcp is disabled in the second router. You may want to consult the dumbAP guide.
Second disable Ipv6 if you are not using it. Under lan interface DHCP settings switch Router Advertisement/DHCPv6/NDP to Disabled.
mmmmmm..... i have a look on dhcp setting for "Interface -> Lan". in IPV6 setting i have all three option to Disabled (Router Advertisement-Service, DHCPv6-Service and the third NDP-Proxy).
I have also read the dumbAP guide but apparently it's for an old version of openwrt ? I have a some different voices and onestly i don't have understand how i need to modify some my current setting.....
Problem is that the dumbAP (like your second router is) doesn't communicate directly with the clients, so the IP won't appear properly because it doesn't exist in the arp table. You can try to periodically do a ping sweep from the dumbAP to renew its arp table if that detail is important to you.
actually it is not that it is so important....... but i have a question:
since in this second DumbAP it's in use for his wireless...... i can set openwrt in some mode to obtain to refresh this arp table as soon as it sees a device connect to its wireless network ?
that is, not a periodic ping... but something that associates this ping with a new connection to the wireless network?
No, the arp table contains the mac to IP bindings. When a station connects only mac is visible to the access point. Some IP communication needs to be done between the AP and the station to update the arp table with the new entry. This is where a periodic ping scan would be helpful.
No, it is resident in the memory.
If you had the net-tools version of arp, you could set static arp entries or import from file, like /etc/ethers. The busybox version is very limited. The only workaround is some periodical ping/arp scan.