在Centos7上玩KVM的话一定要配置网桥的:

[root@localhost nb]# ls /etc/sysconfig/network-scriptsifcfg-8866        ifdown       ifdown-isdn    ifdown-TeamPort  ifup-ib     ifup-post      ifup-tunnel        network-functions-ipv6ifcfg-br0         ifdown-bnep  ifdown-post    ifdown-tunnel    ifup-ippp   ifup-ppp       ifup-wirelessifcfg-CCAP_guest  ifdown-eth   ifdown-ppp     ifup             ifup-ipv6   ifup-routes    init.ipv6-globalifcfg-enp0s25     ifdown-ib    ifdown-routes  ifup-aliases     ifup-isdn   ifup-sit       keys-8866ifcfg-iPak        ifdown-ippp  ifdown-sit     ifup-bnep        ifup-plip   ifup-Team      keys-iPakifcfg-lo          ifdown-ipv6  ifdown-Team    ifup-eth         ifup-plusb  ifup-TeamPort  network-functions

 上面的是配置好的,可以看到新增的文件ifcfg-br0

接下来看看ifcfg-br0 和ifcfg-enp0s25网卡文件:

# cat /etc/sysconfig/network-scripts/ifcfg-br0 TYPE=BridgeBOOTPROTO=dhcpDEFROUTE=yesPEERDNS=yesPEERROUTES=yesIPV4_FAILURE_FATAL=noDEVICE=br0ONBOOT=yes# cat /etc/sysconfig/network-scripts/ifcfg-enp0s25 TYPE=EthernetBOOTPROTO=dhcpDEFROUTE=yesPEERDNS=yesPEERROUTES=yesIPV4_FAILURE_FATAL=noIPV6INIT=yesIPV6_AUTOCONF=yesIPV6_DEFROUTE=yesIPV6_PEERDNS=yesIPV6_PEERROUTES=yesIPV6_FAILURE_FATAL=noIPV6_ADDR_GEN_MODE=stable-privacyNAME=enp0s25UUID=cfe5e123-26a1-4f1d-bcd0-ec8a7a91c82fDEVICE=enp0s25ONBOOT=yesBRIDGE=br0 #只是增加 了这么一条!!!

 重启网卡enp0s25(每个机器的名子不同)

ifdown enp0s25 #先关闭然后重启网卡# systemctl restart network查看成功后的ip:[root@localhost nb]# ip a1: lo: 
     
       mtu 65536 qdisc noqueue state UNKNOWN qlen 1    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 forever2: enp0s25: 
      
        mtu 1500 qdisc pfifo_fast master br0 state UP qlen 1000    link/ether 54:xx:75:4e:37:d9 brd ff:ff:ff:ff:ff:ff3: wlp4s0: 
       
         mtu 1500 qdisc noop state DOWN qlen 1000    link/ether 02:d7:e5:72:e5:c8 brd ff:ff:ff:ff:ff:ff5: virbr0: 
        
          mtu 1500 qdisc noqueue state DOWN qlen 1000    link/ether 52:54:x0:fe:e5:29 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 forever6: virbr0-nic: 
         
           mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 1000    link/ether 52:xx:00:fe:e5:29 brd ff:ff:ff:ff:ff:ff7: vnet0: 
          
            mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether fe:54:00:d6:81:e8 brd ff:ff:ff:ff:ff:ff inet6 fe80::fc54:ff:fed6:81e8/64 scope link valid_lft forever preferred_lft forever8: br0: 
           
             mtu 1500 qdisc noqueue state UP qlen 1000 link/ether 54:ee:75:4e:37:d9 brd ff:ff:ff:ff:ff:ff inet 10.100.0.19/24 brd 10.100.0.255 scope global dynamic br0 #可以看到ip valid_lft 86368sec preferred_lft 86368sec inet6 fe80::56ee:75ff:fe4e:37d9/64 scope link valid_lft forever preferred_lft forever
           
          
         
        
       
      
     

 查看网桥:

# brctl showbridge name	bridge id		STP enabled	interfacesbr0		8000.54ee754e37d9	no		enp0s25virbr0		8000.525400fee529	yes		virbr0-nic