When IPv6 addresses are added to the dnsmasq host file, dnsmasq stops issuing leases

Bug #1316190 reported by Sean M. Collins
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
neutron
Low
Sean M. Collins

Bug Description

When an IPv6 subnet is created, with ipv6_ra_mode not set, and ipv6_address_mode set to "slaac" - ipv6 addresses are added to the host file that dnsmasq uses, and this causes dnsmasq to cease responding to dhcp clients on the v4 side.

Revision history for this message
Sean M. Collins (scollins) wrote :

I will post logs and configuration information from the lab setup shortly.

tags: added: ipv6
Revision history for this message
Sean M. Collins (scollins) wrote :

Contents of the dhcp host file:

stack@osctrl-cc38-b01:/opt/stack/data/neutron/dhcp/2bc9a7db-84f8-4776-a498-ef385e1d8065$ cat host
fa:16:3e:cf:c5:59,host-10-251-2-131.openstacklocal,10.251.2.131
fa:16:3e:cf:c5:59,host-2001-db8-beef-7ac0--1.openstacklocal,[2001:db8:beef:7ac0::1]
fa:16:3e:f8:7a:12,host-10-251-2-130.openstacklocal,10.251.2.130
fa:16:3e:f8:7a:12,host-2001-db8-beef-7ac0-f816-3eff-fef8-7a12.openstacklocal,[2001:db8:beef:7ac0:f816:3eff:fef8:7a12]

Revision history for this message
Sean M. Collins (scollins) wrote :
Download full text (15.9 KiB)

console output from the guest:

[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Linux version 3.2.0-37-virtual (buildd@allspice) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #58-Ubuntu SMP Thu Jan 24 15:48:03 UTC 2013 (Ubuntu 3.2.0-37.58-virtual 3.2.35)
[ 0.000000] Command line: root=/dev/vda console=tty0 console=ttyS0
[ 0.000000] KERNEL supported cpus:
[ 0.000000] Intel GenuineIntel
[ 0.000000] AMD AuthenticAMD
[ 0.000000] Centaur CentaurHauls
[ 0.000000] BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
[ 0.000000] BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
[ 0.000000] BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
[ 0.000000] BIOS-e820: 0000000000100000 - 0000000003ffe000 (usable)
[ 0.000000] BIOS-e820: 0000000003ffe000 - 0000000004000000 (reserved)
[ 0.000000] BIOS-e820: 00000000feffc000 - 00000000ff000000 (reserved)
[ 0.000000] BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
[ 0.000000] NX (Execute Disable) protection: active
[ 0.000000] DMI 2.4 present.
[ 0.000000] No AGP bridge found
[ 0.000000] last_pfn = 0x3ffe max_arch_pfn = 0x400000000
[ 0.000000] PAT not supported by CPU.
[ 0.000000] found SMP MP-table at [ffff8800000f1610] f1610
[ 0.000000] init_memory_mapping: 0000000000000000-0000000003ffe000
[ 0.000000] RAMDISK: 03c65000 - 03ff0000
[ 0.000000] ACPI: RSDP 00000000000f1470 00014 (v00 BOCHS )
[ 0.000000] ACPI: RSDT 0000000003ffe4a0 00030 (v01 BOCHS BXPCRSDT 00000001 BXPC 00000001)
[ 0.000000] ACPI: FACP 0000000003ffff80 00074 (v01 BOCHS BXPCFACP 00000001 BXPC 00000001)
[ 0.000000] ACPI: DSDT 0000000003ffe4d0 01137 (v01 BXPC BXDSDT 00000001 INTL 20100528)
[ 0.000000] ACPI: FACS 0000000003ffff40 00040
[ 0.000000] ACPI: SSDT 0000000003fff700 00838 (v01 BOCHS BXPCSSDT 00000001 BXPC 00000001)
[ 0.000000] ACPI: APIC 0000000003fff610 00078 (v01 BOCHS BXPCAPIC 00000001 BXPC 00000001)
[ 0.000000] No NUMA configuration found
[ 0.000000] Faking a node at 0000000000000000-0000000003ffe000
[ 0.000000] Initmem setup node 0 0000000000000000-0000000003ffe000
[ 0.000000] NODE_DATA [0000000003ff6000 - 0000000003ffafff]
[ 0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00
[ 0.000000] kvm-clock: cpu 0, msr 0:1cf7681, boot clock
[ 0.000000] Zone PFN ranges:
[ 0.000000] DMA 0x00000010 -> 0x00001000
[ 0.000000] DMA32 0x00001000 -> 0x00100000
[ 0.000000] Normal empty
[ 0.000000] Movable zone start PFN for each node
[ 0.000000] early_node_map[2] active PFN ranges
[ 0.000000] 0: 0x00000010 -> 0x0000009f
[ 0.000000] 0: 0x00000100 -> 0x00003ffe
[ 0.000000] ACPI: PM-Timer IO Port: 0xb008
[ 0.000000] ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
[ 0.000000] ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1])
[ 0.000000] ACPI: IOAPIC (id[0x00] address[0xfec00000] gsi_base[0])
[ 0.000000] IOAPIC[0]: apic_id 0, version 17, address 0xfec00000, GSI 0-23
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl d...

Revision history for this message
Sean M. Collins (scollins) wrote :
Download full text (3.5 KiB)

Neutron Network:

+--------------------------------------+---------+--------------------------------------------------------------+
| id | name | subnets |
+--------------------------------------+---------+--------------------------------------------------------------+
| 0574ad5f-a4c2-4e11-8941-d5eceedbcd91 | default | 09dc21a4-d46f-4e80-ab60-7a532f2bf98a 10.251.2.128/27 |
| | | 4674a928-0f7b-452c-a037-950fc1e15ba0 2001:db8:beef:7ac0::/64 |
+--------------------------------------+---------+--------------------------------------------------------------+

Neutron Subnets:

+--------------------------------------+--------------+-------------------------+-------------------------------------------------------------------------------------+
| id | name | cidr | allocation_pools |
+--------------------------------------+--------------+-------------------------+-------------------------------------------------------------------------------------+
| 09dc21a4-d46f-4e80-ab60-7a532f2bf98a | provider_net | 10.251.2.128/27 | {"start": "10.251.2.130", "end": "10.251.2.158"} |
| 4674a928-0f7b-452c-a037-950fc1e15ba0 | v6_slaac_net | 2001:db8:beef:7ac0::/64 | {"start": "2001:db8:beef:7ac0::1", "end": "2001:db8:beef:7ac0:ffff:ffff:ffff:fffe"} |
+--------------------------------------+--------------+-------------------------+-------------------------------------------------------------------------------------+

+-------------------+-------------------------------------------------------------------------------------+
| Field | Value |
+-------------------+-------------------------------------------------------------------------------------+
| allocation_pools | {"start": "2001:db8:beef:7ac0::1", "end": "2001:db8:beef:7ac0:ffff:ffff:ffff:fffe"} |
| cidr | 2001:db8:beef:7ac0::/64 |
| dns_nameservers | |
| enable_dhcp | True |
| gateway_ip | fe80::21c:73ff:fe03:11b3 |
| host_routes | |
| id | 4674a928-0f7b-452c-a037-950fc1e15ba0 |
| ip_version | 6 |
| ipv6_address_mode | slaac |
| ipv6_ra_mode | |
| name | v6_slaac_net ...

Read more...

Changed in neutron:
assignee: nobody → Sean M. Collins (scollins)
status: New → In Progress
Kyle Mestery (mestery)
Changed in neutron:
milestone: none → juno-2
importance: Undecided → Low
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix merged to neutron (master)

Reviewed: https://review.openstack.org/64578
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=1715eb7c8e1f2433df3c081e357f8c40dfe2a28a
Submitter: Jenkins
Branch: master

commit 1715eb7c8e1f2433df3c081e357f8c40dfe2a28a
Author: Sean M. Collins <email address hidden>
Date: Tue Jun 10 15:20:49 2014 -0400

    Ensure entries in dnsmasq belong to a subnet using DHCP

    In certain configurations, Neutron calculates SLAAC addresses for IPv6
    subnets and adds them to the fixed_ips field of a port. Since those
    subnets are not being managed by DHCP, do not add those fixed_ip entries
    to the host file.

    Closes-bug: #1316190
    Related-bug: #1257446

    Change-Id: I77dd55063296990c9df385f331f5de5d42402786

Changed in neutron:
status: In Progress → Fix Committed
Changed in neutron:
status: Fix Committed → Fix Released
Thierry Carrez (ttx)
Changed in neutron:
milestone: juno-2 → 2014.2
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers