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Centos7系统配置上的变化（三）为网络接口添加多IP

2024-07-25 19:50:16   217人阅读

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：

[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254[root@centos7 ~]#[root@centos7 ~]# ip addr show enp0s3 scope global2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff    inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3       valid_lft forever preferred_lft forever[root@centos7 ~]#[root@centos7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0......IPADDR0=192.168.150.110PREFIX0=24GATEWAY0=192.168.150.254DNS1=192.168.150.254HWADDR=08:00:27:15:35:D2IPADDR1=192.168.150.111PREFIX1=24[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 。

 

[root@centos7 ~]# nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0[root@centos7 ~]#[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254[root@centos7 ~]#
[root@centos7 ~]# ip addr show enp0s3 scope global
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3
       valid_lft forever preferred_lft forever
[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。

[root@centos7 ~]# systemctl restart network[root@centos7 ~]#[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254[root@centos7 ~]#[root@centos7 ~]# ip addr show enp0s3 scope global2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff    inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3       valid_lft forever preferred_lft forever[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ping 192.168.150.111PING 192.168.150.111 (192.168.150.111) 56(84) bytes of data.From 192.168.150.110 icmp_seq=1 Destination Host UnreachableFrom 192.168.150.110 icmp_seq=2 Destination Host Unreachable......[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。

[root@centos7 ~]# nmcli dev connect enp0s3[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ip addr show enp0s3 scope global2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff    inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3       valid_lft forever preferred_lft forever    inet 192.168.150.111/24 brd 192.168.150.255 scope global secondary enp0s3       valid_lft forever preferred_lft forever[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ping 192.168.150.111PING 192.168.150.111 (192.168.150.111) 56(84) bytes of data.64 bytes from 192.168.150.111: icmp_seq=1 ttl=64 time=0.039 ms64 bytes from 192.168.150.111: icmp_seq=2 ttl=64 time=0.079 ms......[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：

[root@centos7 ~]# ip addr add 192.168.150.113/24 dev enp0s3[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254IP4.ADDRESS[3]:ip = 192.168.150.112/24, gw = 192.168.150.254IP4.ADDRESS[4]:ip = 192.168.150.113/24, gw = 192.168.150.254[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ip addr show enp0s3 scope global2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff    inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3       valid_lft forever preferred_lft forever    inet 192.168.150.111/24 brd 192.168.150.255 scope global secondary enp0s3       valid_lft forever preferred_lft forever    inet 192.168.150.112/24 brd 192.168.150.255 scope global secondary enp0s3       valid_lft forever preferred_lft forever    inet 192.168.150.113/24 scope global secondary enp0s3       valid_lft forever preferred_lft forever[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ping 192.168.150.113PING 192.168.150.113 (192.168.150.113) 56(84) bytes of data.64 bytes from 192.168.150.113: icmp_seq=1 ttl=64 time=0.098 ms64 bytes from 192.168.150.113: icmp_seq=2 ttl=64 time=0.255 ms......

/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：

[root@centos7 ~]# ip addr del 192.168.150.113/24 dev enp0s3[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254IP4.ADDRESS[2]:ip = 192.168.150.111/24, gw = 192.168.150.254IP4.ADDRESS[3]:ip = 192.168.150.112/24, gw = 192.168.150.254[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ip addr show enp0s3 scope global2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff    inet 192.168.150.110/24 brd 192.168.150.255 scope global enp0s3       valid_lft forever preferred_lft forever    inet 192.168.150.111/24 brd 192.168.150.255 scope global secondary enp0s3       valid_lft forever preferred_lft forever    inet 192.168.150.112/24 brd 192.168.150.255 scope global secondary enp0s3       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 

[root@centos7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0TYPE=EthernetBOOTPROTO=noneDEFROUTE=yesIPV4_FAILURE_FATAL=noIPV6INIT=noIPV6_AUTOCONF=yesIPV6_DEFROUTE=yesIPV6_PEERDNS=yesIPV6_PEERROUTES=yesIPV6_FAILURE_FATAL=noNAME=eth0UUID=295e1841-0ff3-4db9-8800-4e25fc2944daONBOOT=yesIPADDR0=192.168.150.110PREFIX0=24GATEWAY0=192.168.150.254DNS1=192.168.150.254HWADDR=08:00:27:15:35:D2#IPADDR1=192.168.150.111#PREFIX1=24#IPADDR2=192.168.150.112#PREFIX2=24[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0:1TYPE=EthernetBOOTPROTO=noneDEFROUTE=yesIPV4_FAILURE_FATAL=noIPV6INIT=noIPV6_AUTOCONF=yesIPV6_DEFROUTE=yesIPV6_PEERDNS=yesIPV6_PEERROUTES=yesIPV6_FAILURE_FATAL=noNAME=eth0:1DEVICE=eth0:1UUID=295e1841-0ff3-4db9-8800-4e25fc2944daONBOOT=yesIPADDR0=192.168.150.119PREFIX0=24GATEWAY0=192.168.150.254DNS1=192.168.150.254HWADDR=08:00:27:15:35:D2[root@centos7 ~]#[root@centos7 ~]# nmcli con reload[root@centos7 ~]# nmcli dev connect enp0s3[root@centos7 ~]#[root@centos7 ~]# nmcli -t -f IP4.ADDRESS dev show enp0s3IP4.ADDRESS[1]:ip = 192.168.150.110/24, gw = 192.168.150.254[root@centos7 ~]#[root@centos7 ~]#[root@centos7 ~]# ip addr show enp0s3 scope global2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    link/ether 08:00:27:15:35:d2 brd ff:ff:ff:ff:ff:ff    inet 192.168.150.110/24 brd 192.168.150.255 scope global eth0:1       valid_lft forever preferred_lft forever[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


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