Hi,

I'm trying to create instance in OpenStack Victoria. But, I am facing a issues about dhcp of neutron.

I have OpenStack Victoria running in one baremetl server with uniontech os(a downstream of centos 8). I have a Flat network created in the range of 10.12.21.190-10.12.21.195. I selected to have a DHCP. The instance ran, and neutron-dhcp-agent.service had allocated a IP to it. 

# openstack server list +--------------------------------------+-------+--------+-----------------------+----------------+--------+ | ID | Name | Status | Networks | Image | Flavor | +--------------------------------------+-------+--------+-----------------------+----------------+--------+ | 4ccae37e-fbfe-4acb-a109-e1bc9175c2e0 | inst1 | ACTIVE | provider=10.12.21.192 | centos8-server | h2 | +--------------------------------------+-------+--------+-----------------------+----------------+--------+

But the instance can't get a response from DHCP.  No any error in log. And if I setup the ip manually in the instance I can get access to the gateway, dhcp port and external network.

I can catpure the DHCP request in any network device in the server, include dhcp port(10.12.21.190). But no response.  Dnsmasq process was running and had 

# openstack port list +--------------------------------------+------+-------------------+-----------------------------------------------------------------------------+--------+ | ID | Name | MAC Address | Fixed IP Addresses | Status | +--------------------------------------+------+-------------------+-----------------------------------------------------------------------------+--------+ | 5ab32ca8-2d1d-47cf-9a62-7c01d21abaf0 | | fa:16:3e:1d:48:45 | ip_address='10.12.21.192', subnet_id='3daf5a55-e76a-4093-8533-78d9464b1beb' | ACTIVE | | 63fb2306-7759-4933-8d93-590e3a56f315 | | fa:16:3e:c5:59:9a | ip_address='10.12.21.190', subnet_id='3daf5a55-e76a-4093-8533-78d9464b1beb' | ACTIVE | +--------------------------------------+------+-------------------+-----------------------------------------------------------------------------+--------+ # ip netns qdhcp-ec2c4d9d-888b-4312-b0af-ab2127b76e0e (id: 0) # sudo ip netns exec qdhcp-ec2c4d9d-888b-4312-b0af-ab2127b76e0e sudo tcpdump -n -S -i tap63fb2306-77|grep DHCP

## notes: fa:16:3e:1d:48:45 is the mac of nic of inst1 ​

dropped privs to tcpdump tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on tap63fb2306-77, link-type EN10MB (Ethernet), capture size 262144 bytes 16:47:18.194028 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:1d:48:45, length 276 16:47:21.146736 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:1d:48:45, length 276 16:47:25.226387 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:1d:48:45, length 276

more detail informations:

# ps -ef|grep dnsmasq

dnsmasq 7441 1 0 12月03 ? 00:00:00 dnsmasq --no-hosts --no-resolv --pid-file=/var/lib/neutron/dhcp/ec2c4d9d-888b-4312-b0af-ab2127b76e0e/pid --dhcp-hostsfile=/var/lib/neutron/dhcp/ec2c4d9d-888b-4312-b0af-ab2127b76e0e/host --addn-hosts=/var/lib/neutron/dhcp/ec2c4d9d-888b-4312-b0af-ab2127b76e0e/addn_hosts --dhcp-optsfile=/var/lib/neutron/dhcp/ec2c4d9d-888b-4312-b0af-ab2127b76e0e/opts --dhcp-leasefile=/var/lib/neutron/dhcp/ec2c4d9d-888b-4312-b0af-ab2127b76e0e/leases --dhcp-match=set:ipxe,175 --dhcp-userclass=set:ipxe6,iPXE --local-service --bind-dynamic --dhcp-range=set:subnet-3daf5a55-e76a-4093-8533-78d9464b1beb,10.12.21.0,static,255.255.255.0,86400s --dhcp-option-force=option:mtu,1500 --dhcp-lease-max=256 --conf-file= --domain=openstacklocal

dnsmasq 317868 1 0 14:33 ? 00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper

root 317869 317868 0 14:33 ? 00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper

root 340315 317310 0 18:43 pts/2 00:00:00 grep --color=auto dnsmasq

[root@a16 ~]# cat /var/lib/neutron/dhcp/ec2c4d9d-888b-4312-b0af-ab2127b76e0e/host

fa:16:3e:c5:59:9a,host-10-12-21-190.openstacklocal,10.12.21.190

fa:16:3e:1d:48:45,host-10-12-21-192.openstacklocal,10.12.21.192

# ovs-vsctl show adbd4b0c-cb78-4b8f-b8a6-197c5948312c Manager "ptcp:6640:127.0.0.1" is_connected: true Bridge br0 Controller "tcp:127.0.0.1:6633" is_connected: true fail_mode: secure datapath_type: system Port enp5s0 Interface enp5s0 Port phy-br0 Interface phy-br0 type: patch options: {peer=int-br0} Port br0 Interface br0 type: internal Bridge br-tun Controller "tcp:127.0.0.1:6633" is_connected: true fail_mode: secure datapath_type: system Port br-tun Interface br-tun type: internal Port patch-int Interface patch-int type: patch options: {peer=patch-tun} Bridge br-int Controller "tcp:127.0.0.1:6633" is_connected: true fail_mode: secure datapath_type: system Port int-br0 Interface int-br0 type: patch options: {peer=phy-br0} Port br-int Interface br-int type: internal Port tap63fb2306-77 tag: 1 Interface tap63fb2306-77 type: internal Port patch-tun Interface patch-tun type: patch options: {peer=patch-int} Port qvo5ab32ca8-2d tag: 1 Interface qvo5ab32ca8-2d ovs_version: "2.13.0". # ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp5s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master ovs-system state UP group default qlen 1000 link/ether 1c:69:7a:92:be:30 brd ff:ff:ff:ff:ff:ff 3: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether ea:f5:ce:24:93:12 brd ff:ff:ff:ff:ff:ff 4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 1c:69:7a:92:be:30 brd ff:ff:ff:ff:ff:ff inet 10.12.21.142/24 scope global br0 valid_lft forever preferred_lft forever inet6 fe80::1e69:7aff:fe92:be30/64 scope link valid_lft forever preferred_lft forever 5: br-int: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether ba:5d:16:cf:89:40 brd ff:ff:ff:ff:ff:ff inet6 fe80::b85d:16ff:fecf:8940/64 scope link valid_lft forever preferred_lft forever 9: br-tun: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 86:bb:24:69:7e:43 brd ff:ff:ff:ff:ff:ff 11: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:4d:96:e4 brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 12: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:4d:96:e4 brd ff:ff:ff:ff:ff:ff 13: qbr5ab32ca8-2d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 76:0e:be:40:a6:ee brd ff:ff:ff:ff:ff:ff 14: qvo5ab32ca8-2d@qvb5ab32ca8-2d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master ovs-system state UP group default qlen 1000 link/ether 12:90:d5:07:2a:a2 brd ff:ff:ff:ff:ff:ff inet6 fe80::1090:d5ff:fe07:2aa2/64 scope link valid_lft forever preferred_lft forever 15: qvb5ab32ca8-2d@qvo5ab32ca8-2d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master qbr5ab32ca8-2d state UP group default qlen 1000 link/ether 76:0e:be:40:a6:ee brd ff:ff:ff:ff:ff:ff inet6 fe80::740e:beff:fe40:a6ee/64 scope link valid_lft forever preferred_lft forever 16: tap5ab32ca8-2d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master qbr5ab32ca8-2d state UNKNOWN group default qlen 1000 link/ether fe:16:3e:1d:48:45 brd ff:ff:ff:ff:ff:ff inet6 fe80::fc16:3eff:fe1d:4845/64 scope link valid_lft forever preferred_lft forever # cat /etc/neutron/plugins/ml2/openvswitch_agent.ini [ovs] local_ip = 10.12.21.142 datapath_type = system bridge_mappings = provider:br0 [vxlan] enable_vxlan = true local_ip = 10.12.21.142 l2_population = true prevent_arp_spoofing = True [securitygroup] enable_security_group = True firewall_driver = neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver # cat /etc/neutron/dhcp_agent.ini [DEFAULT] interface_driver = neutron.agent.linux.interface.OVSInterfaceDriver dhcp_driver = neutron.agent.linux.dhcp.Dnsmasq enable_isolated_metadata = true

   

I would very very appreciate any kind of guidance or help.

Thanks,

Han Guangyu