[Dnsmasq-discuss] dnsmasq forgets dns records

Discussion:

Stefan Priebe - Profihost AG

2016-01-28 07:00:09 UTC

Hi,

i've a problem where dnsmasq seems to forget the DNS / hostnames.

Those devices affected are debian wheezy machines running dhclient.

Wenn they're freshly booted the .leases entry looks like this:

/var/lib/misc/dnsmasq.leases:1454145111 0c:c4:7a:3a:3f:d6 10.0.20.203
servername *

After some ours the entry looks like this:
/var/lib/misc/dnsmasq.leases:1454145111 0c:c4:7a:3a:3f:d6 10.0.20.203 *
*

The log entry is this one:

Jan 26 14:30:09 server1031-han dnsmasq-dhcp[7212]: 2047084359 client
provides name: servername
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359
DHCPDISCOVER(bond0.100) 0c:c4:7a:3a:3f:d6
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 tags:
server-ok, server_gw, ipmisuperm_mac, server_mac, bond0.100
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359
DHCPOFFER(bond0.100) 10.0.20.203 0c:c4:7a:3a:3f:d6
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 requested
options: 1:netmask, 28:broadcast, 2:time-offset, 3:router,
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 requested
options: 15:domain-name, 6:dns-server, 119:domain-search,
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 requested
options: 12:hostname, 44:netbios-ns, 47:netbios-scope,
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 requested
options: 26:mtu, 121:classless-static-route, 42:ntp-server
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 next
server: 10.0.16.1
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
1 option: 53 message-type 2
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 54 server-identifier 10.0.16.1
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 51 lease-time 259200
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 58 T1 129600
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 59 T2 226800
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 1 netmask 255.255.240.0
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 28 broadcast 10.0.31.255
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 6 dns-server 10.0.16.1
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
25 option: 15 domain-name server.XXX
Jan 26 14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size:
4 option: 3 router 10.0.16.1

Stefan

Simon Kelley

2016-02-01 11:54:38 UTC

Permalink

Post by Stefan Priebe - Profihost AG
Hi,
i've a problem where dnsmasq seems to forget the DNS / hostnames.
Those devices affected are debian wheezy machines running
dhclient.
/var/lib/misc/dnsmasq.leases:1454145111 0c:c4:7a:3a:3f:d6
10.0.20.203 servername *
/var/lib/misc/dnsmasq.leases:1454145111 0c:c4:7a:3a:3f:d6
10.0.20.203 * *
Jan 26 14:30:09 server1031-han dnsmasq-dhcp[7212]: 2047084359
client provides name: servername Jan 26 14:30:12 server1031-han
dnsmasq-dhcp[7212]: 2047084359 DHCPDISCOVER(bond0.100)
0c:c4:7a:3a:3f:d6 Jan 26 14:30:12 server1031-han
dnsmasq-dhcp[7212]: 2047084359 tags: server-ok, server_gw,
ipmisuperm_mac, server_mac, bond0.100 Jan 26 14:30:12
server1031-han dnsmasq-dhcp[7212]: 2047084359 DHCPOFFER(bond0.100)
10.0.20.203 0c:c4:7a:3a:3f:d6 Jan 26 14:30:12 server1031-han
dnsmasq-dhcp[7212]: 2047084359 requested options: 1:netmask,
28:broadcast, 2:time-offset, 3:router, Jan 26 14:30:12
15:domain-name, 6:dns-server, 119:domain-search, Jan 26 14:30:12
12:hostname, 44:netbios-ns, 47:netbios-scope, Jan 26 14:30:12
26:mtu, 121:classless-static-route, 42:ntp-server Jan 26 14:30:12
2047084359 sent size: 1 option: 53 message-type 2 Jan 26 14:30:12
54 server-identifier 10.0.16.1 Jan 26 14:30:12 server1031-han
dnsmasq-dhcp[7212]: 2047084359 sent size: 4 option: 51 lease-time
2047084359 sent size: 4 option: 58 T1 129600 Jan 26 14:30:12
2047084359 sent size: 4 option: 1 netmask 255.255.240.0 Jan 26
14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size: 4
option: 28 broadcast 10.0.31.255 Jan 26 14:30:12 server1031-han
dnsmasq-dhcp[7212]: 2047084359 sent size: 4 option: 6 dns-server
2047084359 sent size: 25 option: 15 domain-name server.XXX Jan 26
14:30:12 server1031-han dnsmasq-dhcp[7212]: 2047084359 sent size: 4
option: 3 router 10.0.16.1

The most likely explanation is that something else got or renewed it's
DHCP lease and asked for the same name. Does servername appear
anywhere else in the leases file?

Cheers,

Simon.

Stefan Priebe

2016-02-01 16:27:16 UTC

Permalink

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The most likely explanation is that something else got or renewed it's
DHCP lease and asked for the same name. Does servername appear
anywhere else in the leases file?

dhcp-fqdn solved the problem.

Thanks for your answer.

Stefan

Cheers,
Simon.
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