Peculiar LAN name resolution issue

[sfx2000]

I haven't done anything except this line in /jffs/configs/dnsmasq.conf.add:

dhcp-host=DE:AD:BE:EF:CA:FE,bar,192.168.1.43,12h

It is also named in NVRAM:

custom_clientlist=<bar>DE:AD:BE:EF:CA:FE>0>0>>

Have you created a hosts file?

if you put that entry into /jffs/configs/hosts.add

192.168.1.43 bar.lan

and kick dnsmasq, it should load up from there...

Configure Hosts File on Asus RT-AX88U Router

Have you ever wondered how to configure local access to an externally accessible resource in your network, via the same domain name? Simple example is a NAS storage. In my case Synology DS918+. After setting up SSL, I realized that I cannot access the NAS locally via the same domain name, only...

www.neolisk.blog

 

[sfx2000]

Being a Microsoft tool, only Microsoft truly knows what is going on under the hood.

Shudder the thought there - I wonder what gymnastics it would have to take with WSL, as glibc would usually help there with things...

 

[RMerlin]

Shudder the thought there - I wonder what gymnastics it would have to take with WSL, as glibc would usually help there with things...

Probably none, as this is Ubuntu code, so the WSL version of nslookup will use whatever the nslookup source code uses.

Keep in mind WSL2 is nothing like Cygwin. The API isn't at the userspace level, it's at the kernel space level.

 

[drinkingbird]

Being a Microsoft tool, only Microsoft truly knows what is going on under the hood.

As far as I know nslookup is truly DNS only, while ping will fail back to NETBIOS and WINS. While WINS is mostly gone these days, netbios names from other windows boxes will ping fine even when nslookup fails.

 

[drinkingbird]

$ nslookup bar.
Server:        127.0.0.53
Address:    127.0.0.53#53

** server can't find bar: SERVFAIL

$ nslookup bar. 192.168.1.1
Server:        192.168.1.1
Address:    192.168.1.1#53

Name:    bar
Address: 192.168.1.43

As you can see, you are not using the router DNS server by default, you're using 127.0.0.53 (probably a loopback on that machine). When you specify 192.168.1.1 it works fine.

First, give yourself a hostname in the asus router, and on any hosts that you have assigned static IPs to. You can use "home" or "lan" or something similar. Personally I like to keep the format traditional so I'd say use like home.net or lan.net or intra.net

If you do have statically assigned hosts I'd recommend setting them to DHCP and instead reserving IPs in the router for them. That way they'll get hostname updates, etc automatically.

Then try again and see what happens. Make sure your devices are in fact using the DHCP assigned (or manually assigned) DNS server and not looking to a local table as primary, as the one above appears to be.

However based on some previous posts in this thread, it appears you may just have some corrupted DNS stuff in the router. How long since you did a factory reset? There may be a way to blow away the DNSMASQ configs and have them rebuilt, never tried doing that. But with these routers, when something is weird, a factory reset and manual reconfig can make a world of difference, sometimes even making other stuff work better that you didn't even realize wasn't working right.

 

[sbsnb]

As a sanity check can you post the output of this command run on your router:

egrep "domain|local" /etc/dnsmasq.conf

admin@RT-AX86U-AA39:/tmp/home/root# egrep "domain|local" /etc/dnsmasq.conf
domain=foo.lan
domain-needed
local=/foo.lan/

 

[ColinTaylor]

OK thanks for confirming that. That's all OK.

Can you now post the complete output of this from the affected Windows PC:

ipconfig /all

Also, are you using any non-default settings or scripts that would affect DNS? For example, DNSFilter, DNSSEC, DoT, dnscrypt-proxy, etc.

 

[sbsnb]

Windows IP Configuration

   Host Name . . . . . . . . . . . . : DESKTOP-62ERGU1
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : foo.lan

Ethernet adapter Ethernet 2:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) I211 Gigabit Network Connection #2
   Physical Address. . . . . . . . . : 04-D9-F5-1E-30-30
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Wi-Fi:

   Connection-specific DNS Suffix  . : foo.lan
   Description . . . . . . . . . . . : ASUS PCE-AC88 802.11ac Network Adapter
   Physical Address. . . . . . . . . : DE-AD-BE-EF-CA-FE
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::15ac:7738:a391:ab2%5(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.20(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Thursday, November 3, 2022 11:59:06 AM
   Lease Expires . . . . . . . . . . : Friday, November 4, 2022 06:33:41 AM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DHCPv6 IAID . . . . . . . . . . . : 137166241
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-24-E9-CE-0C-04-D9-F5-1E-30-30
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

DNSFilter: Router
DoT: Strict

 

[ColinTaylor]

That all looks OK as well. So I'm at a complete loss because those configuration settings seem to contradict the output you're getting from nslookup.

So I'm out of ideas. At this point I'd just be repeating the same loop we went through before when you had a similar problem in March. Back then you resolved it by un-mounting the remnants of an old script.

 

[L&LD]

What antivirus do you have (or had) running?

Anything like Zone Alarm, or similar?

 

[sbsnb]

What antivirus do you have (or had) running?

Anything like Zone Alarm, or similar?

No. On the Linux machine there's nothing. The Windows machine just has the default "Windows Security."

 

[sbsnb]

That all looks OK as well. So I'm at a complete loss because those configuration settings seem to contradict the output you're getting from nslookup.

So I'm out of ideas. At this point I'd just be repeating the same loop we went through before when you had a similar problem in March. Back then you resolved it by un-mounting the remnants of an old script.

I have no scripts installed that are related to DNS at all at this point. The only DNS settings that are different from default is changing the "DNS Privacy Protocol" from "None" to DoT.