保留vip与dhcp续订

Question

我有一个奇怪的问题，当我收到一个新的DHCP更新请求时，我的vip被从我的界面上移除。日志显示了以下内容：

Jun  1 17:00:06 lb1 dhclient: DHCPREQUEST of 10.0.0.2 on eth0 to 10.0.0.3 port 67 (xid=0x6deab016)
Jun  1 17:00:06 lb1 dhclient: DHCPNAK from 10.0.0.3 (xid=0x6deab016)
Jun  1 17:00:06 lb1 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x37e1db6a)
Jun  1 17:00:06 lb1 dhclient: DHCPREQUEST of 10.0.0.2 on eth0 to 255.255.255.255 port 67 (xid=0x37e1db6a)
Jun  1 17:00:06 lb1 dhclient: DHCPOFFER of 10.0.0.2 from 10.0.0.3
Jun  1 17:00:06 lb1 dhclient: DHCPACK of 10.0.0.2 from 10.0.0.3
Jun  1 17:00:06 lb1 dhclient: bound to 10.0.0.2 -- renewal in 38223 seconds.
Jun  1 17:00:07 lb1 ntpd[1321]: Deleting interface #8 eth0, 10.0.255.254#123, interface stats: received=7, sent=0, dropped=0, active_time=145198 secs
Jun  1 17:00:07 lb1 ntpd[1321]: peers refreshed

此时，vip ip (10.0.255.254)被从接口中移除，并且不会被转移到其他被保存的实例上。

工作的ip a命令输出：

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    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 forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether fa:16:3e:cf:35:ac brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.2/16 brd 10.0.255.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 10.0.255.254/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fecf:35ac/64 scope link
       valid_lft forever preferred_lft forever

当dhcp更新运行时：

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    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 forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether fa:16:3e:cf:35:ac brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.2/16 brd 10.0.255.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fecf:35ac/64 scope link
       valid_lft forever preferred_lft forever

接口文件：

# 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 dhcp

当我重新启动对实例的保留时，vip将再次添加到接口中。所以问题是为什么dhcp要移除vip？

Answer 1

我最近也遇到了同样的问题。我正在使用OpenStack运行两个keepalived实例。我注意到，当实例更新其IP地址时，有时keepalived会认为IP地址被移除，然后在稍后重新添加。这足以让它释放贵宾，但没有将它们重新添加到主keepalived实例中，也不足以让备用实例接管贵宾。

在查看了keepalived的S文档之后，我发现了一个名为dont_track_primary的选项，它可以添加到vrrp实例中，我将该选项添加到了所有的vrrp实例中，此后就没有出现过这个问题。