[Dnsmasq-discuss] No DHCP on eth1
Eldon Ziegler
eldonz at atlanticdb.com
Wed Nov 17 10:43:48 GMT 2010
We are downsizing an app that runs on multiple servers onto a single
server but are not getting DHCP responses from dnsmasq on eth1. It works
correctly when dnsmasq is run on a separate server.
dnsmasq-2.45-1.1.el5_3 from Red Hat is running.
Virtual machines are started dynamically (using QEMU-KVM) and are
connected to tap0 and tap1 on bridge virbr0. All MAC to IP address
assignments are via /etc/ethers.
sudo brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.00259010282a no tap1
tap0
eth1
tcpdump shows the DHCP requests on eth1.
listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes
05:19:42.338702 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:00:01, length: 300
05:19:43.150538 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:01:01, length: 300
05:19:47.149363 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:01:01, length: 300
05:19:51.150423 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:01:01, length: 300
05:19:58.152492 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:01:01, length: 300
05:19:58.336652 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:00:01, length: 300
05:20:12.189338 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:50:56:01:01:01, length: 300
The log shows no indication that dnsmasq saw the messages.
Nov 17 05:19:33 allin1 kernel: virbr0: topology change detected, propagating
Nov 17 05:19:33 allin1 kernel: virbr0: port 2(tap0) entering forwarding state
Nov 17 05:19:34 allin1 kernel: virbr0: topology change detected, propagating
Nov 17 05:19:34 allin1 kernel: virbr0: port 3(tap1) entering forwarding state
Nov 17 05:23:02 allin1 dnsmasq[8997]: exiting on receipt of SIGTERM
Extracts from dnsmasq.conf
#interface=eth0
interface=eth1
#interface=eth2
#interface=eth3
no-dhcp-interface=eth0
no-dhcp-interface=eth2
dhcp-range=10.0.0.230,static,255.255.0.0,10m
dhcp-range=10.1.0.230,static,255.255.0.0,10m
dhcp-range=10.2.0.230,static,255.255.0.0,10m
dhcp-range=10.3.0.230,static,255.255.0.0,10m
dhcp-range=10.4.0.230,static,255.255.0.0,10m
dhcp-range=10.5.0.230,static,255.255.0.0,10m
dhcp-range=10.6.0.230,static,255.255.0.0,10m
dhcp-range=10.7.0.230,static,255.255.0.0,10m
dhcp-range=10.8.0.230,static,255.255.0.0,10m
dhcp-range=10.9.0.230,static,255.255.0.0,10m
dhcp-range=10.10.0.230,static,255.255.0.0,10m
cat /etc/ethers
00:50:56:01:00:01 10.0.1.0
00:50:56:01:01:01 10.0.1.1
eth1 Link encap:Ethernet HWaddr 00:25:90:10:28:2A
inet addr:10.0.0.1 Bcast:10.0.255.255 Mask:255.255.0.0
inet6 addr: fe80::225:90ff:fe10:282a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:117 errors:0 dropped:0 overruns:0 frame:0
TX packets:427 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:17430 (17.0 KiB) TX bytes:76864 (75.0 KiB)
Memory:d8020000-d8040000
eth1:101 Link encap:Ethernet HWaddr 00:25:90:10:28:2A
inet addr:10.0.0.101 Bcast:10.0.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:d8020000-d8040000
tap0 Link encap:Ethernet HWaddr 06:4E:13:A2:24:EC
inet6 addr: fe80::44e:13ff:fea2:24ec/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:10 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:1836 (1.7 KiB) TX bytes:1800 (1.7 KiB)
tap1 Link encap:Ethernet HWaddr 2A:9C:E6:EF:BD:B0
inet6 addr: fe80::289c:e6ff:feef:bdb0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:5 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:1800 (1.7 KiB) TX bytes:1186 (1.1 KiB)
virbr0 Link encap:Ethernet HWaddr 00:25:90:10:28:2A
inet addr:10.0.0.101 Bcast:10.0.255.255 Mask:255.255.0.0
inet6 addr: fe80::225:90ff:fe10:282a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:453 errors:0 dropped:0 overruns:0 frame:0
TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:88453 (86.3 KiB) TX bytes:3737 (3.6 KiB)
sudo netstat -nlp | grep dnsmasq
tcp 0 0 0.0.0.0:53 0.0.0.0:* LISTEN 9254/dnsmasq
tcp 0 0 :::53 :::* LISTEN 9254/dnsmasq
udp 0 0 0.0.0.0:53 0.0.0.0:* 9254/dnsmasq
udp 0 0 0.0.0.0:67 0.0.0.0:* 9254/dnsmasq
udp 0 0 :::53 :::* 9254/dnsmasq
Connection to the LAN is on eth2.
Note, a cross over cable is used between eth0 and eth1 to get the NICs
in "RUNNING" mode. The DHCP request messages did not appear on eth1
until this cable was installed.
Any suggestions will be appreciated.
Eldon
More information about the Dnsmasq-discuss
mailing list