[Dnsmasq-discuss] Repeated assignment, ignored dhcp-host, and failed DNS lookup

Mon Oct 8 16:43:17 BST 2012

Let me preface by saying that I've been using dnsmasq for a couple of years, without known problems until today.

Today, after having been away for a week, I tried to connect with an internal server as I've done many, many times, but DNS lookup failed.

So, on the server that's running dnsmasq, I typed (where m1330c is the server in question), and the response was:

> Server: 127.0.0.1
> Address: 127.0.0.1#53
>
> Non-authoritative answer:
> *** Can't find m1330c: No answer

Now, let me point out that m1330c has a wireless interface and a wired interface.  And both of these are specified in the dnsmasq.conf with preferred addresses, in the format:
dhcp-host=11:22:33:44:55:66,m1330c,192.168.0.6
dhcp-host=11:22:33:44:55:67,m1330cw,192.168.0.7

I get the same nslookup response for m1330cw

Upon review of the messages log, I found that different addresses are being assigned (.14 and .15, respectively)... and not only that, but the assignment is being made every 50-some seconds.

This has been set-it-and-forget-it for me, and I don't remember a lot of the details I went through for the initial configuration, but I do know that it was working, and now has stopped, but without configuration changes.  A reboot of the server running dnsmasq did not resolve the issue.

There are a few devices on the network.  Three have hard-coded addresses (in /etc/hosts), and nslookup shows accurate information for them.  Those with DHCP-based addresses all return "can't find ..." messages.

Final bit of information: It appears that the repeat-ip-serving for m1330c/w has been going on for months, but did not seem to impact operation.  But it seems to happen only to these two interfaces (a Windows 7 server, but not the only one in the net).

To summarize:

nslookup does not return IP address of DHCP-based servers
"dhcp-host" entries in /etc/dnsmasq.conf are ignored, or at least are not as expected
Repeated assignment of IP address to two interfaces

Following are the messages from dnsmasq since time of boot.  What might I be missing?

Oct  8 10:46:46 stora-1 dnsmasq[2046]: started, version 2.62 cachesize 150
Oct  8 10:46:46 stora-1 dnsmasq[2046]: compile time options: IPv6 GNU-getopt no-DBus no-i18n no-IDN DHCP DHCPv6 no-Lua TFTP no-conntrack
Oct  8 10:46:46 stora-1 dnsmasq-dhcp[2046]: DHCP, IP range 192.168.0.10 -- 192.168.0.109, lease time 7d
Oct  8 10:46:46 stora-1 dnsmasq-tftp[2046]: TFTP root is /home/tftpd
Oct  8 10:46:46 stora-1 dnsmasq[2046]: reading /etc/resolv.conf
Oct  8 10:46:46 stora-1 dnsmasq[2046]: using nameserver 65.32.5.112#53
Oct  8 10:46:46 stora-1 dnsmasq[2046]: using nameserver 65.32.5.111#53
Oct  8 10:46:46 stora-1 dnsmasq[2046]: read /etc/hosts - 258 addresses
Oct  8 10:46:58 stora-1 dnsmasq[2046]: reading /etc/resolv.conf
Oct  8 10:46:58 stora-1 dnsmasq[2046]: using nameserver 65.32.5.112#53
Oct  8 10:46:58 stora-1 dnsmasq[2046]: using nameserver 65.32.5.111#53
Oct  8 10:46:58 stora-1 dnsmasq[2046]: ignoring nameserver 127.0.0.1 - local interface
Oct  8 10:47:35 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:47:35 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:47:35 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:47:35 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:48:35 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:48:35 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:48:36 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:48:36 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:49:37 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:49:37 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:49:37 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:49:37 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:50:41 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:50:41 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:50:41 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:50:41 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:51:42 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:51:42 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:51:42 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:51:42 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:53:35 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:53:35 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:53:35 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:53:35 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:54:36 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:54:36 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:54:37 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:54:37 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw
Oct  8 10:55:37 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.14 00:21:9b:cb:e6:dd
Oct  8 10:55:37 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.14 00:21:9b:cb:e6:dd M1330C
Oct  8 10:55:41 stora-1 dnsmasq-dhcp[2046]: DHCPINFORM(eth0) 192.168.0.15 00:21:5c:6a:03:ef
Oct  8 10:55:41 stora-1 dnsmasq-dhcp[2046]: DHCPACK(eth0) 192.168.0.15 00:21:5c:6a:03:ef m1330cw

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