DHCP Relay not sending DHCP OFFER packets

Bug #1686192 reported by J. Kary on 2017-04-25
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
dnsmasq (Ubuntu)
Undecided
Unassigned

Bug Description

In Ubuntu Server 17-04. DNSMASQ version 2.76-5

DHCP Relay option for DNSMASQ appears to be broken. The syslog states the file is allocating an IP address but TCPDUMP shows no DHCP OFFER is ever sent out on the receiving interface.

Configuration is included with the bug report. This problem seems to occur in centOS as well.

Looking at an strace it appears to be calling sendmsg however no outgoing DHCP packet is seen on the wire via TCPDUMP.

jkary@DHCP-UBUNTU-SERVER:~$ sudo su -
[sudo] password for jkary:
root@DHCP-UBUNTU-SERVER:~# tcpdump -i ens160 port 67 or port 68 -n
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ens160, link-type EN10MB (Ethernet), capture size 262144 bytes
08:02:12.056671 IP 10.168.102.1.67 > 10.168.101.20.67: BOOTP/DHCP, Request from 00:0c:29:b5:9b:0e, length 322
08:02:16.420010 IP 10.168.102.1.67 > 10.168.101.20.67: BOOTP/DHCP, Request from 00:0c:29:65:e0:ea, length 322
08:02:21.522334 IP 10.168.102.1.67 > 10.168.101.20.67: BOOTP/DHCP, Request from 00:0c:29:65:e0:ea, length 322
^C
3 packets captured
3 packets received by filter
0 packets dropped by kernel
root@DHCP-UBUNTU-SERVER:~# tail -50 /var/log/syslog
Apr 25 08:02:19 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 28 broadcast 10.168.102.255
Apr 25 08:02:19 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 3 router 10.168.102.1
Apr 25 08:02:19 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 6 dns-server 10.168.101.20
Apr 25 08:02:19 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 20 option: 82 agent-id 01:0a:01:08:00:06:00:4c:4f:2a:00:2f:02:06...
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 available DHCP range: 10.168.102.100 -- 10.168.102.150
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 DHCPDISCOVER(ens160) 00:0c:29:65:e0:ea
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 tags: ens160
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 DHCPOFFER(ens160) 10.168.102.128 00:0c:29:65:e0:ea
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 1:netmask, 28:broadcast, 2:time-offset, 121:classless-static-route,
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 15:domain-name, 6:dns-server, 12:hostname,
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 40:nis-domain, 41:nis-server, 42:ntp-server,
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 26:mtu, 119:domain-search, 3:router, 121:classless-static-route,
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 249, 33:static-route, 252, 42:ntp-server
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 next server: 10.168.101.20
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 1 option: 53 message-type 2
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 54 server-identifier 10.168.101.20
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 51 lease-time 12h
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 58 T1 6h
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 59 T2 10h30m
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 1 netmask 255.255.255.0
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 28 broadcast 10.168.102.255
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 3 router 10.168.102.1
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 6 dns-server 10.168.101.20
Apr 25 08:02:21 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 20 option: 82 agent-id 01:0a:01:08:00:06:00:4c:4f:2a:00:2f:02:06...
Apr 25 08:02:29 DHCP-UBUNTU-SERVER kernel: [ 2251.555545] device ens160 left promiscuous mode
Apr 25 08:02:29 DHCP-UBUNTU-SERVER systemd-timesyncd[647]: Timed out waiting for reply from 91.189.91.157:123 (ntp.ubuntu.com).
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 available DHCP range: 10.168.102.100 -- 10.168.102.150
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 DHCPDISCOVER(ens160) 00:0c:29:65:e0:ea
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 tags: ens160
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 DHCPOFFER(ens160) 10.168.102.128 00:0c:29:65:e0:ea
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 1:netmask, 28:broadcast, 2:time-offset, 121:classless-static-route,
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 15:domain-name, 6:dns-server, 12:hostname,
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 40:nis-domain, 41:nis-server, 42:ntp-server,
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 26:mtu, 119:domain-search, 3:router, 121:classless-static-route,
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 requested options: 249, 33:static-route, 252, 42:ntp-server
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 next server: 10.168.101.20
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 1 option: 53 message-type 2
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 54 server-identifier 10.168.101.20
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 51 lease-time 12h
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 58 T1 6h
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 59 T2 10h30m
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 1 netmask 255.255.255.0
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 28 broadcast 10.168.102.255
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 3 router 10.168.102.1
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 4 option: 6 dns-server 10.168.101.20
Apr 25 08:02:35 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 3576154470 sent size: 20 option: 82 agent-id 01:0a:01:08:00:06:00:4c:4f:2a:00:2f:02:06...
Apr 25 08:02:40 DHCP-UBUNTU-SERVER systemd-timesyncd[647]: Timed out waiting for reply from 91.189.89.198:123 (ntp.ubuntu.com).
Apr 25 08:02:43 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 1465560618 available DHCP range: 10.168.102.100 -- 10.168.102.150
Apr 25 08:02:43 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 1465560618 vendor class: MSFT 5.0
Apr 25 08:02:43 DHCP-UBUNTU-SERVER dnsmasq-dhcp[2241]: 1465560618 client provides name: WIN-MAAQ6LSC4L4
root@DHCP-UBUNTU-SERVER:~#

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: dnsmasq 2.76-5 [modified: etc/dnsmasq.conf]
ProcVersionSignature: Ubuntu 4.10.0-19.21-generic 4.10.8
Uname: Linux 4.10.0-19-generic x86_64
ApportVersion: 2.20.4-0ubuntu4
Architecture: amd64
Date: Tue Apr 25 07:51:06 2017
InstallationDate: Installed on 2017-04-25 (0 days ago)
InstallationMedia: Ubuntu-Server 17.04 "Zesty Zapus" - Release amd64 (20170412)
PackageArchitecture: all
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: dnsmasq
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.dnsmasq.conf: 2017-04-25T07:38:15.895525

J. Kary (jkary-98) wrote :
Joshua Powers (powersj) wrote :

Hi! Thanks for reporting this and including your configuration file. Given you are seeing this across distros I think this warrants an upstream report. Would you be willing to file something upstream and provide a link back in this bug report? Thanks!

tags: added: needs-upstream-report
J. Kary (jkary-98) wrote :

I am happy to report this bug upstream however I've been unable to find a bug tracker for DNSMASQ specifically.

Take Care
Jason

Joshua Powers (powersj) wrote :

Looks like they use a mailing list for bug reports:

<email address hidden>
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss

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