[kolla-ansible][yoga][neutron][neutron-dhcp]ERRORS.... Need to understand
Franck VEDEL
franck.vedel at univ-grenoble-alpes.fr
Wed Apr 5 20:15:41 UTC 2023
Hi,
thanks a lot Brian,
and thanks to Sahid (for his help today, in french :) )
Problem is very small MTU.
a user (student) created a network with a small mtu (on the day of the final exam) and for the rest of the day, no more dhcp....
The problem is addressed here: https://bugs.launchpad.net/neutron/+bug/1988069 <https://bugs.launchpad.net/neutron/+bug/1988069>
Before I have time to update, if it happens again, I will know what to do…
Thanks a lot
Franck VEDEL
Dép. Réseaux Informatiques & Télécoms
IUT1 - Univ GRENOBLE Alpes
0476824462
Stages, Alternance, Emploi.
> Le 5 avr. 2023 à 15:37, Brian Haley <haleyb.dev at gmail.com> a écrit :
>
> Hi,
>
> On 4/5/23 2:57 AM, Franck VEDEL wrote:
>> Hi , and thanks a lot for your help.
>> so
>> $ sudo ip netns exec qdhcp-8db375e0-28d2-4379-9330-397dc9b4f2b1 ip a
>> 3401: tap1c220d25-b9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 68qdisc noqueue state UNKNOWN group default qlen 1000
>> link/ether fa:16:3e:20:ef:bc brd ff:ff:ff:ff:ff:ff
>> inet 169.254.169.254/32 brd 169.254.169.254 scope global tap1c220d25-b9
>> valid_lft forever preferred_lft forever
>> inet 10.1.42.1/24 brd 10.1.42.255 scope global tap1c220d25-b9
>> valid_lft forever preferred_lft forever
>
> Ok, so it is as I thought, someone has set a very small mtu on a network.
>
>> $tail -f /var/log/kolla/neutron/neutron-dhcp-agent.log |grep 8db375e0-28d2-4379-9330-397dc9b4f2b1
>> 2023-04-05 08:36:11.558 7 INFO neutron.agent.dhcp.agent [-] Starting network 8db375e0-28d2-4379-9330-397dc9b4f2b1 dhcp configuration
>> 2023-04-05 08:36:12.532 7 ERROR neutron.agent.dhcp.agent [-] Unable to enable dhcp for 8db375e0-28d2-4379-9330-397dc9b4f2b1.: neutron.privileged.agent.linux.ip_lib.InvalidArgument: Invalid parameter/value used on interface tap1c220d25-b9, namespace qdhcp-8db375e0-28d2-4379-9330-397dc9b4f2b1.
>> 2023-04-05 08:36:12.532 7 ERROR neutron.agent.dhcp.agent neutron.privileged.agent.linux.ip_lib.InvalidArgument: Invalid parameter/value used on interface tap1c220d25-b9, namespace qdhcp-8db375e0-28d2-4379-9330-397dc9b4f2b1.
>> 2023-04-05 08:36:12.534 7 INFO neutron.agent.dhcp.agent [-] Finished network 8db375e0-28d2-4379-9330-397dc9b4f2b1 dhcp configuration
>> openstack network show 8db375e0-28d2-4379-9330-397dc9b4f2b1
>> +---------------------------+--------------------------------------+
>> | Field | Value |
>> +---------------------------+--------------------------------------+
>> | admin_state_up | UP |
>> | availability_zone_hints | |
>> | availability_zones | nova |
>> | created_at | 2023-04-04T11:49:47Z |
>> | description | |
>> | dns_domain | None |
>> | id | 8db375e0-28d2-4379-9330-397dc9b4f2b1 |
>> | ipv4_address_scope | None |
>> | ipv6_address_scope | None |
>> | is_default | None |
>> | is_vlan_transparent | None |
>> | mtu |68 |
>> | name | NET1 |
>> | port_security_enabled | True |
>> | project_id | 6d6cbcbb6e8d4264bcd13dd8b3d79466 |
>> | provider:network_type | vxlan |
>> | provider:physical_network | None |
>> | provider:segmentation_id | 456 |
>> | qos_policy_id | None |
>> | revision_number | 2 |
>> | router:external | Internal |
>> | segments | None |
>> | shared | False |
>> | status | ACTIVE |
>> | subnets |b72cf65c-1a22-4165-a55b-884bcc9c636a|
>> | tags | |
>> | updated_at | 2023-04-04T11:49:47Z |
>> +---------------------------+———————————————————+
>
> Increasing the mtu on this network to at least 1280 should fix the issue with DHCP, that is the IPv6 minimum mtu and most likely causing the issue. You should check other networks and use the same value, but it is probably 1450 given the overlay is vxlan.
>
> Since this is a known issue, there is no need for a new bug, but for your reference you can go to https://bugs.launchpad.net/neutron <https://bugs.launchpad.net/neutron> to search and file a new one.
>
> Thanks,
>
> -Brian
>
>
>> $openstack subnet showb72cf65c-1a22-4165-a55b-884bcc9c636a
>> +----------------------+--------------------------------------+
>> | Field | Value |
>> +----------------------+--------------------------------------+
>> | allocation_pools | 10.1.42.1-10.1.42.253 |
>> | cidr | 10.1.42.0/24 |
>> | created_at | 2023-04-04T11:49:47Z |
>> | description | |
>> | dns_nameservers | |
>> | dns_publish_fixed_ip | None |
>> | enable_dhcp | True |
>> | gateway_ip | 10.1.42.254 |
>> | host_routes | |
>> | id | b72cf65c-1a22-4165-a55b-884bcc9c636a |
>> | ip_version | 4 |
>> | ipv6_address_mode | None |
>> | ipv6_ra_mode | None |
>> | name | |
>> | network_id | 8db375e0-28d2-4379-9330-397dc9b4f2b1 |
>> | project_id | 6d6cbcbb6e8d4264bcd13dd8b3d79466 |
>> | revision_number | 0 |
>> | segment_id | None |
>> | service_types | |
>> | subnetpool_id | None |
>> | tags | |
>> | updated_at | 2023-04-04T11:49:47Z |
>> +----------------------+--------------------------------------+
>> Since yesterday, we have a lot of network (2 per students , 100 students) , so a lot of errors:
>> In the log of dnsmask we can see this:
>> Apr 5 08:55:02 dnsmasq-dhcp[2466928]: read /var/lib/neutron/dhcp/7d33855e-03a8-431b-9cf8-64f8e95b8f93/host
>> Apr 5 08:55:02 dnsmasq-dhcp[2466928]: read /var/lib/neutron/dhcp/7d33855e-03a8-431b-9cf8-64f8e95b8f93/opts
>> Apr 5 08:55:05 dnsmasq-dhcp[609053]: DHCPDISCOVER(tap5af0e639-f3) fa:16:3e:8d:86:b9 no address available
>> Apr 5 08:55:05 dnsmasq-dhcp[4572]: DHCPDISCOVER(tap6fe70972-c9) fa:16:3e:6d:dc:c8 no address available
>> You say: If that's not it please file a new bug with all the above info provided.
>> How can I do that ?
>> Thanks a lot
>> Franck
>>> Le 5 avr. 2023 à 00:00, Brian Haley <haleyb.dev at gmail.com <mailto:haleyb.dev at gmail.com> <mailto:haleyb.dev at gmail.com <mailto:haleyb.dev at gmail.com>>> a écrit :
>>>
>>> 8db375e0-28d2-4379-9330-397dc9b4f2b1
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