文中写的noarp的配置我认为不完全对。

...
net.ipv4.ip_forward = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
...

这样的配置在网络上到处都是，不知道为什么？

To disable ARP for VIP at real servers, we just need to set arp_announce/arp_ignore sysctls at the interface connected to the VIP network. For example, real servers have eth0 connected to the VIP network with the VIP at interface lo, we will have the following commands.

上面一段文字是从lvs.org的wiki中摘的，意思是"必须配置链接到vip网络的接口的arp_announce/arp_ignore".假设RIP是配置在eth0上，VIP是配置在lo上，那么应该这样配置：
net.ipv4.conf.eth0.arp_ignore = 1
net.ipv4.conf.eth0.arp_announce = 2