[Dnsmasq-discuss] How to troubleshoot NXDOMAIN for local devices?

[Geert Stappers]

On Thu, Feb 15, 2018 at 10:46:27PM +0000, Andy Ruddock wrote:
> Todd Andrews wrote:
> > Hi All,
> > 
> > I'm running dnsmasq 2.76 on a Raspberry Pi.

FWIW there are 2.79 release candidates.


> > It's been working great for
> > months but today I started seeing an odd behavior for a specific local
> > device and I don't know how to troubleshoot it.
> > 
> > The device is a Dell Inspiron 5577 Windows 10 Home edition laptop with the
> > latest Windows updates. It's getting an IP address of 192.168.1.115.

What did choose the  .115  ??

> > I first noticed the problem when I tried to establish a VNC connection to it
> > because I can't connect via its hostname, "sagan", but I can connect via
> > its IP address.

Is hostname "sagan" really configured inside the Windows 10 Home edition laptop??


> > Neither the IP assignment nor the laptop's MAC address appear in
> > dnsmasq.leases. The only reason I know it is assigned .115 is by physically
> > going to the laptop and running the Windows 'ipconfig' program at the
> > command prompt.
> > 
> > I've rebooted the Raspberry Pi and the Windows 10 laptop, but it hasn't
> > made a difference.
> > 
> > More info below. Does anyone have any ideas?
> > 
> > Regards,
> > Todd
> 
> 
> Are you sure the windows box hasn't been configured with a static IP
> address?
> 
> Any information when you refresh the IP address from within a cmd window
> in Windows?
> 	ipconfig /renew
> 
> > 
> > 
> > 1. dnsmasq.log shows:
> > /var/log/dnsmasq.log:Feb 15 12:38:34 dnsmasq[738]: config 192.168.1.115 is NXDOMAIN

Yes, that is problem original poster has.

> > 2. I believe the following are the relevant dnsmasq config file entries.
> > These have been working for quite some time. I'm obfuscating the full MAC
> > address:
> > 
> > dhcp-host=f4:8e:38:xx:xx:xx,sagan

That is MAC-address and hostname.
Where is the "connection" / "link"  with  IP-address?


And about MAC-address:
 * How many MAC addresses has the laptop?
 * Are you using the right one?
 * What was done to prevent typo errors?

> > domain=si.loc
> > local=/si.loc/
> > expand-hosts
> > 
> > 
> > 3.  $ dnsmasq --test
> > dnsmasq: syntax check OK.
> > 
> > 
> > 4. Using the program WinIPConfig2012 a.k.a. WinIPConfig 4.0
> > <http://www.pkostov.com/wordpress/?p=19>, I've verified that the laptop is
> > using the Raspberry Pi as the DHCP server. There's no other DHCP server on
> > my network that I know of.
> > 
> > 5. On a third computer, a Macintosh, I get these results.

The third computer, what is the hostname?

> > The Raspberry Pi is at 192.168.1.40.
> > 
> > $ ping sagan
> >       *ping: cannot resolve sagan: Unknown host*
> > $ ping sagan.si.loc
> >       *ping: cannot resolve sagan.si.loc: Unknown host*
> > 

Does it work for the hostname of the third computer?


Groeten
Geert Stappers
-- 
Leven en laten leven