如何定义默认关闭的辅助 IP 地址

Question

我可以通过添加行在同一网卡上定义辅助 IP 地址

auto eth0:1
iface eth0:1 inet static
        address 192.168.9.101
        ...

到/etc/network/interfaces。

这为我提供了一个 IP 地址，我可以使用ifup和打开或关闭该地址ifdown。但是，默认情况下它是打开的。通过阅读手册页，似乎默认情况下将其关闭，我只需要删除该行auto eth0:1. 但是，这使得 ifup/down 根本不起作用。

有没有办法做到这一点？

更新：好的，所以问题比我想象的要简单得多。这是我最初所做的：

root@dev003:~# cat /etc/network/interfaces 
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
    address 192.168.2.101
    netmask 255.255.0.0
    network 192.168.0.0
    broadcast 192.168.255.255
    gateway 192.168.1.1
    # dns-* options are implemented by the resolvconf package, if installed
    dns-nameservers 192.168.1.1

auto eth0:1
iface eth0:1 inet static
    address 192.168.9.101
    netmask 255.255.0.0
    network 192.168.0.0
    broadcast 192.168.255.255
    gateway 192.168.1.1
    # dns-* options are implemented by the resolvconf package, if installed
    dns-nameservers 192.168.1.1

root@dev003:~# /etc/init.d/networking restart
 * Reconfiguring network interfaces...                                                                                                                       ssh stop/waiting
ssh start/running, process 3339
ssh stop/waiting
ssh start/running, process 3373
                                                                                                                                                      [ OK ]
root@dev003:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:03:43:82  
          inet addr:192.168.2.101  Bcast:192.168.255.255  Mask:255.255.0.0
          inet6 addr: fe80::a00:27ff:fe03:4382/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2836310 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2806585 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:220309837 (220.3 MB)  TX bytes:187167315 (187.1 MB)

eth0:1    Link encap:Ethernet  HWaddr 08:00:27:03:43:82  
          inet addr:192.168.9.101  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1909267 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1909267 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:160262241 (160.2 MB)  TX bytes:160262241 (160.2 MB)

root@dev003:~# sed -i 's/auto eth0:1/#auto eth0:1/' /etc/network/interfaces 
root@dev003:~# /etc/init.d/networking restart
 * Reconfiguring network interfaces...                                                                                                                       SIOCDELRT: No such process
ssh stop/waiting
ssh start/running, process 3787
                                                                                                                                                      [ OK ]
root@dev003:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:03:43:82  
          inet addr:192.168.2.101  Bcast:192.168.255.255  Mask:255.255.0.0
          inet6 addr: fe80::a00:27ff:fe03:4382/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2840372 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2810267 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:220637496 (220.6 MB)  TX bytes:187451978 (187.4 MB)

eth0:1    Link encap:Ethernet  HWaddr 08:00:27:03:43:82  
          inet addr:192.168.9.101  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1911328 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1911328 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:160435069 (160.4 MB)  TX bytes:160435069 (160.4 MB)

root@dev003:~# ifdown eth0:1
ifdown: interface eth0:1 not configured

这是我卡住的地方，并认为在这样的配置中使用 ifup/down 有问题。事实证明，解决方案非常简单：

root@dev003:~# ifup eth0:1
ssh stop/waiting
ssh start/running, process 3829
root@dev003:~# ifdown eth0:1
root@dev003:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:03:43:82  
          inet addr:192.168.2.101  Bcast:192.168.255.255  Mask:255.255.0.0
          inet6 addr: fe80::a00:27ff:fe03:4382/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2840609 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2810473 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:220656625 (220.6 MB)  TX bytes:187469288 (187.4 MB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1911447 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1911447 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:160445053 (160.4 MB)  TX bytes:160445053 (160.4 MB)

感谢@Gilles 叫我出去，感谢@Marius 提供替代解决方案。

Answer 1

我不知道您是否可以使用ifup/实现这一点ifdown，但是您可以在运行时通过执行从接口添加或删除 IP 地址

ip addr add 192.168.9.101/32 dev eth0

和

ip addr del 192.168.9.101/32 dev eth0

反而。

您不需要为此定义任何虚拟的 'eth0:1' 接口（尽管您可以，如果您愿意，可以通过label eth0:1在 前面添加dev eth0，我认为。我从来没有看到这一点。）。

最后，如果您在某个时候改变主意并决定默认情况下可以使用此辅助 IP，您可以在 /etc/network/interfaces 中执行此操作：

auto eth0
iface eth0 inet ...
    ... whatever you have there already for eth0 ...
    up ip addr add 192.168.9.101/32 dev eth0