Centos7系统配置上的变化（三）为网络接口添加多IP

原文 Centos7系统配置上的变化（三）为网络接口添加多IP

• 实验的方法有 nmtui, 编辑ifcfg-*文件，ip addr 指令，子连接配置文件。
  一、nmtui手工添加IP

  

  看一下当前网络设备的IP，为了精简指令输出，指令就要复杂一些了：

  view sourceprint?

  01.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  02.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  03.[root@centos7 ~]#

  04.[root@centos7 ~]# ip addr show enp0s3 scope global

  05.2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  06.link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff

  07.inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3

  08.valid_lft forever preferred_lft forever

  09.[root@centos7 ~]#

  10.[root@centos7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

  11.......

  12.IPADDR0=192.168.150.110

  13.PREFIX0=24

  14.GATEWAY0=192.168.150.254

  15.DNS1=192.168.150.254

  16.HWADDR=08:00:27:15:35:D2

  17.IPADDR1=192.168.150.111

  18.PREFIX1=24

  19.[root@centos7 ~]#

  新IP已经被加入到ifcfg-eth0中，原始地址的关键字是 IPADDR0、PREFIX0，新地址的关键字是 IPADDR1、PREFIX1 。

  view sourceprint?

  1.[root@centos7 ~]# nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0

  2.[root@centos7 ~]#

  3.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  4.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  5.[root@centos7 ~]#<br>[root@centos7 ~]# ip addr show enp0s3 scope global<br>2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000<br>    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff<br>    inet 192.168.150.110/24 brd192.168.150.255 scope global enp0s3<br>       valid_lft forever preferred_lft forever<br>[root@centos7 ~]#

  load connection 后，NetworkManager 也没有知晓新增IP，新增IP也没有出现在 ip addr show 中。

  view sourceprint?

  01.[root@centos7 ~]# systemctl restart network

  02.[root@centos7 ~]#

  03.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  04.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  05.IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254

  06.[root@centos7 ~]#

  07.[root@centos7 ~]# ip addr show enp0s3 scope global

  08.2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  09.link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff

  10.inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3

  11.valid_lft forever preferred_lft forever

  12.[root@centos7 ~]#

  13.[root@centos7 ~]#

  14.[root@centos7 ~]# ping 192.168.150.111

  15.PING 192.168.150.111 (192.168.150.111) 56(84) bytes of data.

  16.From 192.168.150.110 icmp_seq=1 Destination Host Unreachable

  17.From 192.168.150.110 icmp_seq=2 Destination Host Unreachable

  18.......

  19.[root@centos7 ~]#

  重启network服务后，NetworkManager 知晓新增IP了，但新增IP还是没有生效。

  view sourceprint?

  01.[root@centos7 ~]# nmcli dev connect enp0s3

  02.[root@centos7 ~]#

  03.[root@centos7 ~]#

  04.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  05.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  06.IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254

  07.[root@centos7 ~]#

  08.[root@centos7 ~]#

  09.[root@centos7 ~]# ip addr show enp0s3 scope global

  10.2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  11.link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff

  12.inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3

  13.valid_lft forever preferred_lft forever

  14.inet 192.168.150.111/24 brd 192.168.150.255 scope global secondary enp0s3

  15.valid_lft forever preferred_lft forever

  16.[root@centos7 ~]#

  17.[root@centos7 ~]#

  18.[root@centos7 ~]# ping 192.168.150.111

  19.PING 192.168.150.111 (192.168.150.111) 56(84) bytes of data.

  20.64 bytes from 192.168.150.111: icmp_seq=1 ttl=64 time=0.039 ms

  21.64 bytes from 192.168.150.111: icmp_seq=2 ttl=64 time=0.079 ms

  22.......

  23.[root@centos7 ~]#

  重新连接设备 enp0s3，新IP生效了。注意：不需要先断开设备（nmcli dev disconnect enp0s3），断开设备的话ssh立刻断线。重新连接设备的过程中，ssh是不会断线的。

  nmtui添加IP后，需要： nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0 nmcli dev connect enp0s3

   

  二、手工添加IP到ifcfg-eth0

  在ifcfg-eth0配置文件中手工添加如下两行： IPADDR2=192.168.150.112 PREFIX2=24
  先执行 nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0 后，在nmtui中可以看到新增IP。（也可以简单的用 nmcli con reload ，reload 和 load的区别自己脑补一下吧。） 再执行 nmcli dev connect enp0s3 后，IP 192.168.150.112 才生效的。

  手工添加IP到ifcfg-eth0后，需要： nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0 或 nmcli con reload nmcli dev connect enp0s3

  三、用ip addr add指令添加/删除IP，即刻生效，重启不保留。
  在线添加IP：

  view sourceprint?

  01.[root@centos7 ~]# ip addr add 192.168.150.113/24 dev enp0s3

  02.[root@centos7 ~]#

  03.[root@centos7 ~]#

  04.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  05.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  06.IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254

  07.IP4.ADDRESS[3]:ip = 192.168.150.112/24, gw = 192.168.150.254

  08.IP4.ADDRESS[4]:ip = 192.168.150.113/24, gw = 192.168.150.254

  09.[root@centos7 ~]#

  10.[root@centos7 ~]#

  11.[root@centos7 ~]# ip addr show enp0s3 scope global

  12.2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  13.link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff

  14.inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3

  15.valid_lft forever preferred_lft forever

  16.inet 192.168.150.111/24 brd 192.168.150.255 scope global secondary enp0s3

  17.valid_lft forever preferred_lft forever

  18.inet 192.168.150.112/24 brd 192.168.150.255 scope global secondary enp0s3

  19.valid_lft forever preferred_lft forever

  20.inet 192.168.150.113/24 scope global secondary enp0s3

  21.valid_lft forever preferred_lft forever

  22.[root@centos7 ~]#

  23.[root@centos7 ~]#

  24.[root@centos7 ~]# ping 192.168.150.113

  25.PING 192.168.150.113 (192.168.150.113) 56(84) bytes of data.

  26.64 bytes from 192.168.150.113: icmp_seq=1 ttl=64 time=0.098 ms

  27.64 bytes from 192.168.150.113: icmp_seq=2 ttl=64 time=0.255 ms

  28.......

  /etc/sysconfig/network-scripts/ifcfg-eth0 配置文件里并没有192.168.150.113，所以重启后该IP不会保留。
  在线删除IP：

  view sourceprint?

  01.[root@centos7 ~]# ip addr del 192.168.150.113/24 dev enp0s3

  02.[root@centos7 ~]#

  03.[root@centos7 ~]#

  04.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  05.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  06.IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254

  07.IP4.ADDRESS[3]:ip = 192.168.150.112/24, gw = 192.168.150.254

  08.[root@centos7 ~]#

  09.[root@centos7 ~]#

  10.[root@centos7 ~]# ip addr show enp0s3 scope global

  11.2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  12.link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff

  13.inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3

  14.valid_lft forever preferred_lft forever

  15.inet 192.168.150.111/24 brd 192.168.150.255 scope global secondary enp0s3

  16.valid_lft forever preferred_lft forever

  17.inet 192.168.150.112/24 brd 192.168.150.255 scope global secondary enp0s3

  18.valid_lft forever preferred_lft forever

  四、使用子连接配置文件 ifcfg-*:n
  子连接配置文件是 Centos6 常用的方法，即：如果当前网卡配置文件为 ifcfg-eth0，则子连接配置文件可以为 ifcfg-eth0:1，并且文件中需要写明 DEVICE=eth0:1 ， IPADDR=<新IP地址> 。 我们试试在Centos7 中是否也支持。理论上应该是不支持的，因为在Centos7的网络连接配置文件（即 ifcfg-*）中，DEVICE关键字已经具有了新的定义，即我们上篇说的“设备”。参考上篇 http://www.cnblogs.com/panblack/p/Centos7-WhatsNew-02-networking.html

  首先注释掉ifcfg-eth0中的其他地址，复制 ifcfg-eth0 为 ifcfg-eth0:1，编辑ifcfg-eth0:1， DEVICE 设为eth0:1 ，IP设为 192.168.150.119 ，然后 nmcli con reload ， nmcli dev con enp0s3

  view sourceprint?

  01.[root@centos7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

  02.TYPE=Ethernet

  03.BOOTPROTO=none

  04.DEFROUTE=yes

  05.IPV4_FAILURE_FATAL=no

  06.IPV6INIT=no

  07.IPV6_AUTOCONF=yes

  08.IPV6_DEFROUTE=yes

  09.IPV6_PEERDNS=yes

  10.IPV6_PEERROUTES=yes

  11.IPV6_FAILURE_FATAL=no

  12.NAME=eth0

  13.UUID=295e1841-0ff3-4db9-8800-4e25fc2944da

  14.ONBOOT=yes

  15.IPADDR0=192.168.150.110

  16.PREFIX0=24

  17.GATEWAY0=192.168.150.254

  18.DNS1=192.168.150.254

  19.HWADDR=08:00:27:15:35:D2

  20.#IPADDR1=192.168.150.111

  21.#PREFIX1=24

  22.#IPADDR2=192.168.150.112

  23.#PREFIX2=24

  24. 

  25.[root@centos7 ~]#

  26.[root@centos7 ~]#

  27.[root@centos7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0:1

  28.TYPE=Ethernet

  29.BOOTPROTO=none

  30.DEFROUTE=yes

  31.IPV4_FAILURE_FATAL=no

  32.IPV6INIT=no

  33.IPV6_AUTOCONF=yes

  34.IPV6_DEFROUTE=yes

  35.IPV6_PEERDNS=yes

  36.IPV6_PEERROUTES=yes

  37.IPV6_FAILURE_FATAL=no

  38.NAME=eth0:1

  39.DEVICE=eth0:1

  40.UUID=295e1841-0ff3-4db9-8800-4e25fc2944da

  41.ONBOOT=yes

  42.IPADDR0=192.168.150.119

  43.PREFIX0=24

  44.GATEWAY0=192.168.150.254

  45.DNS1=192.168.150.254

  46.HWADDR=08:00:27:15:35:D2

  47.[root@centos7 ~]#

  48.[root@centos7 ~]# nmcli con reload

  49.[root@centos7 ~]# nmcli dev connect enp0s3

  50.[root@centos7 ~]#

  51.[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3

  52.IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254

  53.[root@centos7 ~]#

  54.[root@centos7 ~]#

  55.[root@centos7 ~]# ip addr show enp0s3 scope global

  56.2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  57.link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff

  58.inet 192.168.150.110/24 brd 192.168.150.255 scope global eth0:1

  59.valid_lft forever preferred_lft forever

  60.[root@centos7 ~]#

  可以看到ifcfg-eth0:1里的新IP确实没有生效。
  五、总结

  ip addr show 中显示的IP才是有效的。 ip addr add 能在线添加IP，立即生效，但重启即丢。 ip addr del 能在线删除IP，立即生效，但重启即丢。 子连接(ifcfg-*:n)已经无效了。 nmtui和编辑ifcfg-eth0 文件效果基本相同，都不能立即生效，必须 load 连接再重新connect网络设备，即： nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0 或 nmcli reload nmcli dev connect enp0s3

Centos7系统配置上的变化（三）为网络接口添加多IP

原文：http://www.cnblogs.com/lonelyxmas/p/4261270.html