[Dnsmasq-discuss] SOLVED Re: No DHCP on eth1

Eldon Ziegler eldonz at atlanticdb.com
Wed Nov 17 20:50:48 GMT 2010


Thanks. Including interface=virbr0 got it working.

On Wed, 2010-11-17 at 08:34 -0600, richardvoigt at gmail.com wrote:
> The logical interface is virbr0.  eth1 is only an enslaved physical
> interface and is not seen by applications such as dnsmasq.
> 
> On Wed, Nov 17, 2010 at 4:43 AM, Eldon Ziegler <eldonz at atlanticdb.com> wrote:
> > 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
> >
> >
> >
> > _______________________________________________
> > Dnsmasq-discuss mailing list
> > Dnsmasq-discuss at lists.thekelleys.org.uk
> > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> >




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