Cannot get local DNS working for devices with DHCP config (ASUS RT-AX86U PRO)

[BosseSwede]

I have never gotten local access between computers working on my home LAN without manually entering the target devices into the hosts file on each computer (both Windows and Linux).
I really dislike this because if a computer connects to the LAN using a new ethernet adapter it gets a new IP from my router via DHCP but that is then not used for other devices so they cannot connect. What can I do to get all devices get the correct IP of another device from the ASUS RT-AX86U PRO router if they use the device's host name to connect?
Should not the router know the hostname/IP connection when it has assigned all device IP addresses itself via DHCP?
Is it a router setting or is it a local setting (different for Linux and Windows then I assume)?
Or can it not be done?

Router stock f/w is: 3.0.0.6.102_34349

 

[bennor]

FYI, you may want to move your post to the correct subforum: ASUS AX Routers & Adapters (Wi-Fi 6/6e), This current subforum (ASUS AC Routers & Adapters (Wi-Fi 5)) discusses the older AC series of Asus routers.

If you are having trouble with local LAN device names not being resolved correctly by the router perhaps try assigning manual IP reservations for your local main LAN clients where you can set a Hostname for those clients. See LAN > DHCP Server page in the router GUI. Otherwise check that each local network client has a hostname set within the device itself. Or try renaming the devices in the Network Map > Client Status section by selecting each client and changing their name and see if that fixes your issue (may not).

PS: It appears currently one cannot set Guest Network Pro client hostnames (by manually reserving IP addresses for them) within the router GUI when the Guest Network Pro option "Use same subnet as main LAN" is disabled for that Guest Network.

 

[dave14305]

Are all the LAN clients using the router IP for DNS lookups? No DNS servers configured on the LAN DHCP Server page of the router?

 

[bbunge]

I have never gotten local access between computers working on my home LAN without manually entering the target devices into the hosts file on each computer (both Windows and Linux).
I really dislike this because if a computer connects to the LAN using a new ethernet adapter it gets a new IP from my router via DHCP but that is then not used for other devices so they cannot connect. What can I do to get all devices get the correct IP of another device from the ASUS RT-AX86U PRO router if they use the device's host name to connect?
Should not the router know the hostname/IP connection when it has assigned all device IP addresses itself via DHCP?
Is it a router setting or is it a local setting (different for Linux and Windows then I assume)?
Or can it not be done?

Router stock f/w is: 3.0.0.6.102_34349

The router does know the hostnames if the client has one. But that does not mean the SMB protocol will use it. Windows usually works out which client will be a WINS server. If that does not work you may need to set one up. Merlin firmware can set the Samba server to be a WINS server so you may want to try the Merlin firmware. You snou.d be able to set a Linux box as a WINS server as well.

 

[ColinTaylor]

The router does know the hostnames if the client has one. But that does not mean the SMB protocol will use it. Windows usually works out which client will be a WINS server. If that does not work you may need to set one up. Merlin firmware can set the Samba server to be a WINS server so you may want to try the Merlin firmware. You snou.d be able to set a Linux box as a WINS server as well.

WINS servers are long since depreciated and should no long used. Windows/SMB clients don't need WINS to resolve local names, they can use normal NetBIOS broadcast as well as LLMNR, DNS, mDNS, DNS-SD, etc.

As @dave14305 said, the problem is likely to be that the clients are not using the router as their DNS server.

He asked the same question three years ago here but never bothered to follow up the latest replies.

 

[BosseSwede]

As @dave14305 said, the problem is likely to be that the clients are not using the router as their DNS server.

Well, that was really the premise of my question....
A bunch of computers on the same LAN managed by the ASUS router to get their local addresses, yet they cannot talk to each other...

Isn't the router supplying the DNS settings to connecting clients also, and does it not include itself then?

Then it seems that it should add itself as one of the servers to be able to supply IP addresses for devices it has itself provided the address to.
And my problem is not for Windows, I have only two such machines on my LAN (my and my wife's laptops) all other computers are linux boxes (or TV sets etc). The example was that a linux box could not ping my Windows laptop (or any other device) for that matter by its hostname.
So I have to edit the hosts file on each Linux box I want to be able to communicate inside the LAN. Very tedious.

And a second item:
The computers do not always use the same network interface, sometimes Ethernet and sometimes WiFi and the Ethernet may well change too if you plug in a docking station with an Ethernet adapter. That gives them a different IP address which the router knows about...

 

[BosseSwede]

FYI, you may want to move your post to the correct subforum: ASUS AX Routers & Adapters (Wi-Fi 6/6e), This current subforum (ASUS AC Routers & Adapters (Wi-Fi 5)) discusses the older AC series of Asus routers.

How can I move a thread?

 

[bennor]

How can I move a thread?

If you cannot move it yourself, ask a mod to do it.

 

[ColinTaylor]

Well, that was really the premise of my question....
A bunch of computers on the same LAN managed by the ASUS router to get their local addresses, yet they cannot talk to each other...

Isn't the router supplying the DNS settings to connecting clients also, and does it not include itself then?

Then it seems that it should add itself as one of the servers to be able to supply IP addresses for devices it has itself provided the address to.
And my problem is not for Windows, I have only two such machines on my LAN (my and my wife's laptops) all other computers are linux boxes (or TV sets etc). The example was that a linux box could not ping my Windows laptop (or any other device) for that matter by its hostname.
So I have to edit the hosts file on each Linux box I want to be able to communicate inside the LAN. Very tedious.

And a second item:
The computers do not always use the same network interface, sometimes Ethernet and sometimes WiFi and the Ethernet may well change too if you plug in a docking station with an Ethernet adapter. That gives them a different IP address which the router knows about...

When a DHCP client connects to your network you should see its IP address and host name being registered in the DNS server:

Mar 18 13:55:54 dnsmasq-dhcp[32309]: DHCPDISCOVER(br0) d8:5e:d3:8a:68:7e
Mar 18 13:55:54 dnsmasq-dhcp[32309]: DHCPOFFER(br0) 192.168.1.152 d8:5e:d3:8a:68:7e
Mar 18 13:55:54 dnsmasq-dhcp[32309]: DHCPREQUEST(br0) 192.168.1.152 d8:5e:d3:8a:68:7e
Mar 18 13:55:54 dnsmasq-dhcp[32309]: DHCPACK(br0) 192.168.1.152 d8:5e:d3:8a:68:7e ubuntu

The name should now be listed on the router's System Log - DHCP leases page.

Confirm that your Ubuntu clients are using the router as their DNS server:

# resolvectl status
Global
         Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
  resolv.conf mode: stub
        DNS Domain: home.lan

Link 2 (eno1)
    Current Scopes: DNS
         Protocols: +DefaultRoute -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.1.1
       DNS Servers: 192.168.1.1

Link 3 (wlo2)
    Current Scopes: none
         Protocols: -DefaultRoute -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported

 

[BosseSwede]

Confirm that your Ubuntu clients are using the router as their DNS server:

$ resolvectl status
Global
         Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
  resolv.conf mode: stub

Link 2 (enp86s0)
    Current Scopes: DNS
         Protocols: +DefaultRoute -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.119.1  <== ASUS Router address
       DNS Servers: 192.168.119.1  <== ASUS Router address
        DNS Domain: xxxxxxxx

Link 3 (wlo1)
    Current Scopes: none
         Protocols: -DefaultRoute -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported

 

[ColinTaylor]

$ resolvectl status
Global
         Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
  resolv.conf mode: stub

Link 2 (enp86s0)
    Current Scopes: DNS
         Protocols: +DefaultRoute -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.119.1  <== ASUS Router address
       DNS Servers: 192.168.119.1  <== ASUS Router address
        DNS Domain: xxxxxxxx

Link 3 (wlo1)
    Current Scopes: none
         Protocols: -DefaultRoute -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported

What about the first half of my previous post?

Also, post the complete output of this command:

nslookup otherhost

where otherhost is the host name that you cannot reach without adding it to your hosts file.

 

[BosseSwede]

What about the first half of my previous post?

I don't understand that at all....
No suggestion of any actual command to try.
Don't know from where/how you took the text you showed.

Also, post the complete output of this command:

nslookup otherhost

where otherhost is the host name that you cannot reach without adding it to your hosts file.

This is done on one of my Ubuntu server's command line:

$ nslookup capella
;; Got SERVFAIL reply from 127.0.0.53
Server:         127.0.0.53
Address:        127.0.0.53#53
** server can't find capella: SERVFAIL

$ nslookup ubuntusrvnuc
;; Got SERVFAIL reply from 127.0.0.53
Server:         127.0.0.53
Address:        127.0.0.53#53

** server can't find ubuntusrvnuc: SERVFAIL

capella is my Windows laptop with ethernet cable plugged into a USB3 connected "docking station"
ubuntusrvnuc is my newly built Ubuntu 24.04.1 server
I have no idea what 127.0.0.53 even is...
It is not an address on my LAN in any case.

 

[ColinTaylor]

I don't understand that at all....
No suggestion of any actual command to try.
Don't know from where/how you took the text you showed.

That information is shown in the router's webUI on the System Log - General Log page (when the client connects). As I said, also look at the router's System Log - DHCP leases page to confirm the same information.

This is done on one of my Ubuntu server's command line:

$ nslookup capella
;; Got SERVFAIL reply from 127.0.0.53
Server:         127.0.0.53
Address:        127.0.0.53#53
** server can't find capella: SERVFAIL

$ nslookup ubuntusrvnuc
;; Got SERVFAIL reply from 127.0.0.53
Server:         127.0.0.53
Address:        127.0.0.53#53

** server can't find ubuntusrvnuc: SERVFAIL

capella is my Windows laptop with ethernet cable plugged into a USB3 connected "docking station"
ubuntusrvnuc is my newly built Ubuntu 24.04.1 server
I have no idea what 127.0.0.53 even is...
It is not an address on my LAN in any case.

Is this server the same one you ran the resolvectl status command on? If not, do it again.

Is this server called ubuntusrvnuc? In other words, is this server trying to lookup its own name?

What output do you get from these commands on this Ubuntu server:

nslookup capella 192.168.119.1
nslookup ubuntusrvnuc 192.168.119.1