virsh

 

 

  <interface type='bridge'>
      <mac address='fa:16:3e:07:4f:e6'/>
      <source bridge='brq07e0cfa1-17'/>
      <target dev='tap36ab4e20-b9'/>
      <model type='virtio'/>
      <alias name='net0'/>

[root@x86compute01 ~]# brctl show | grep brq07e0cfa1-17
brq07e0cfa1-17          8000.80693348e5f3       no              eth3.1018
[root@x86compute01 ~]# brctl show brq07e0cfa1-17
bridge name     bridge id               STP enabled     interfaces
brq07e0cfa1-17          8000.80693348e5f3       no              eth3.1018
                                                        tap072726f0-9e
                                                        tap36ab4e20-b9
                                                        tap39b89d04-01
                                                        tap50e98e5c-7c
                                                        tap5cd371cb-ae
                                                        tap86ac8424-dd
                                                        tap886ad6ad-95
                                                        tapa0fcf5e3-7b
                                                        tapa2d15d3f-d0
                                                        tapbae1e208-d2
                                                        tapbe4b01e2-56
                                                        tapc0787db9-80
                                                        tapcd243c6a-83
                                                        tape38639a7-f3
                                                        tape409411f-a2
                                                        tape6388f29-4e
                                                        vnet1
                                                        vnet4
                                                        vnet7

[root@x86compute01 ~]# brctl show brq07e0cfa1-17 | grep tap36ab4e20-b9
                                                        tap36ab4e20-b9
[root@x86compute01 ~]# tcpdump -i tap36ab4e20-b9 proto ospf
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap36ab4e20-b9, link-type EN10MB (Ethernet), capture size 262144 bytes
19:22:55.283298 IP 10.10.18.148 > 224.0.0.5: OSPFv2, Hello, length 44
19:23:05.283287 IP 10.10.18.148 > 224.0.0.5: OSPFv2, Hello, length 44
^C

[root@x86compute01 ~]# ip a show tap36ab4e20-b9    -----------没有ip
302: tap36ab4e20-b9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master brq07e0cfa1-17 state UNKNOWN group default qlen 1000
    link/ether fe:16:3e:07:4f:e6 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc16:3eff:fe07:4fe6/64 scope link 
       valid_lft forever preferred_lft forever
[root@x86compute01 ~]# 

[root@x86compute01 ~]# ip a show tap36ab4e20-b9
302: tap36ab4e20-b9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master brq07e0cfa1-17 state UNKNOWN group default qlen 1000
    link/ether fe:16:3e:07:4f:e6 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc16:3eff:fe07:4fe6/64 scope link 
       valid_lft forever preferred_lft forever
[root@x86compute01 ~]# virsh dumpxml instance-00003aa6  | grep 10.10.19
[root@x86compute01 ~]# cat proc/net/arp
cat: proc/net/arp: 没有那个文件或目录
[root@x86compute01 ~]# virsh dumpxml instance-00003aa6  | grep "mac address"
      <mac address='fa:16:3e:07:4f:e6'/>
[root@x86compute01 ~]# virsh net-list
 名称               状态     自动开始  持久
----------------------------------------------------------

[root@x86compute01 ~]# arp -an fa:16:3e:07:4f:e6
fa:16:3e:07:4f:e6: 未知的主机
[root@x86compute01 ~]#  virsh domiflist instance-00003aa6  
接口     类型     源        型号      MAC
-------------------------------------------------------
tap36ab4e20-b9 bridge     brq07e0cfa1-17 virtio      fa:16:3e:07:4f:e6

[root@x86compute01 ~]# 

虚拟网卡tap device就是一个dhcp设备，它不会有静态ip，而对应的dhcp服务是由dnsmasq实现的， dhcp服务的host-file中保存着这些tap device的mac地址对应的ip

docker exec -it neutron_dhcp_agent bash

neutron-dhcp-agent)[neutron@controller2 /]$ cd /var/lib/neutron/dhcp/07e0cfa1-1701-44d6-a835-432192448ad9/
(neutron-dhcp-agent)[neutron@controller2 07e0cfa1-1701-44d6-a835-432192448ad9]$  grep 10.10.18.148 *    
addn_hosts:10.10.18.148 focal.kc.local. focal
host:fa:16:3e:07:4f:e6,focal.kc.local.,10.10.18.148

 controller1 、controller2都有有94ec94a9-88d3-4974-a1f5-8e86efa66a63这个namespace，dhcp有这个ip的配置

(neutron-dhcp-agent)[neutron@controller1 07e0cfa1-1701-44d6-a835-432192448ad9]$ grep 10.10.18.148 *
addn_hosts:10.10.18.148 host-10-10-18-148.openstacklocal host-10-10-18-148
host:fa:16:3e:07:4f:e6,host-10-10-18-148.openstacklocal,10.10.18.148