官网：http://www.linuxvirtualserver.org/index.html

中文资料：
LVS项目介绍          http://www.linuxvirtualserver.org/zh/lvs1.html
LVS集群的体系结构    http://www.linuxvirtualserver.org/zh/lvs2.html
LVS集群中的IP负载均衡技术    http://www.linuxvirtualserver.org/zh/lvs3.html
LVS集群的负载调度    http://www.linuxvirtualserver.org/zh/lvs4.html

早在2.2内核时，IPVS就已经以内核补丁的形式出现

从2.4.23版本开始，IPVS软件就合并到Linux内核常用版本的内核补丁的集合

从2.4.24以后IPVS已经成为Linux官方标准内核的一部分

1 lsmod |grep ip_vs #查看系统的LVS模块->默认没有加载模块，需安装管理工具才会激活 2 yum -y install ipvsadm

1 [root@lb03 ~]# ipvsadm -ln
2 IP Virtual Server version 1.2.1 (size=4096)
3 Prot LocalAddress:Port Scheduler Flags
4   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
5 [root@lb03 ~]# lsmod|grep ip_vs
6 ip_vs                 141092  0
7 nf_conntrack          133387  1 ip_vs
8 libcrc32c              12644  3 xfs,ip_vs,nf_conntrack

1 ip addr add 10.0.0.13/24 dev eth0 #lb服务的IP地址可扩展性较差，故使用VIP地址(删除del；显示show)

1 ipvsadm -C

1 ipvsadm --set 30 5 60 #控制浏览器与lb01的超时时间

1 ipvsadm -A -t 10.0.0.13:80 -s wrr -p 20 2 3 #LVS默认无80端口，需另外添加新的虚拟IP记录->控制lb01与web01、web02的超时时间

1 ipvsadm -a -t 10.0.0.13:80 -r 10.0.0.17:80 -g -w 1
2
3 ipvsadm -a -t 10.0.0.13:80 -r 10.0.0.18:80 -g -w 1

1 [root@lb03 ~]# ipvsadm -ln
2 IP Virtual Server version 1.2.1 (size=4096)   #LVS版本号
3 Prot LocalAddress:Port Scheduler Flags     #协议(TCP)本地IP：端口 调度算法 标志(持续时间20s)
4   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
5     #后端节点IP：端口          工作模式 权重 已建立连接 正在连接
6 TCP  10.0.0.3:80 wrr persistent 20
7   -> 10.0.0.17:80                 Route   1      0          0
8   -> 10.0.0.18:80                 Route   1      0          0

1 ip addr add 10.0.0.13/32 dev lo

1 cat >>/etc/sysctl.conf<<EOF   #其目的是为了让rs顺利发送mac地址给客户端
2 net.ipv4.conf.all.arp_ignore = 1
3 net.ipv4.conf.all.arp_announce = 2
4 net.ipv4.conf.lo.arp_ignore = 1
5 net.ipv4.conf.lo.arp_announce = 2
6 EOF
7
8 sysctl -p

 1 [root@lb03 ~]# ip a s eth0
 2 eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
 3  link/ether 00:50:56:3b:cb:36 brd ff:ff:ff:ff:ff:ff
 4  inet 10.0.0.13/24 scope global secondary eth0
 5     valid_lft forever preferred_lft forever
 6 [root@web03 ~]# ip a s lo
 7 lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
 8  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
 9 inet 10.0.0.13/32 scope global lo
10     valid_lft forever preferred_lft forever

1 http://10.0.0.13/

1 [root@lb04 ~]# arp -n
2 Address                  HWtype  HWaddress           Flags Mask            Iface
3 10.0.0.254               ether   00:50:56:e9:9f:2c   C                     eth0
4 10.0.0.18                ether   00:0c:29:ea:ca:55   C                     eth0
5 10.0.0.13                ether   00:0c:29:de:7c:97   C                     eth0
6 172.16.1.15              ether   00:0c:29:de:7c:a1   C                     eth1
7 10.0.0.17                ether   00:0c:29:4a:ac:4a   C                     eth0

1 arp-a   #Windows查看ARP缓存命令
2 arp-n   #Linux查看ARP缓存命令
3 arping -c 1 -I eth0 10.0.0.6
4 #Linux解析IP对应的MAC地址[-c指定超时的ARP数据包数量；-I指定使用哪个网络接口]

1 arping -I eth0 -c 1 -U VIP 2 arping -I eth0 -c 1 -U 10.0.0.13

1 [root@lb03 ~]# ip addr del 10.0.0.13/24 dev eth0
2 [root@lb04 ~]# ip addr add 10.0.0.13/24 dev eth0
3 [root@lb04 ~]# arping -I eth0 -c 1 -U 10.0.0.13
4 ARPING 10.0.0.13 from 10.0.0.13 eth0
5 Sent 1 probes (1 broadcast(s))
6 Received 0 response(s)

windows查看arp -a

1 [e:\~]$ arp -a

2.3.3 LVS集群的工作模式

DR直接路由模式

NAT模式

FULLNAT

TUNNEL

1 yum install -y keepalived

 1 [root@lb03 ~]# cat /etc/keepalived/keepalived.conf
 2 global_defs {
 3    router_id LVS_01
 4 }
 5
 6 vrrp_instance VI_1 {
 7     state MASTER
 8     interface eth0
 9     virtual_router_id 51
10     priority 150
11     advert_int 1
12     authentication {
13         auth_type PASS
14         auth_pass 1111
15     }
16     virtual_ipaddress {
17      10.0.0.13/24
18     }
19 }
20
21 virtual_server 10.0.0.13 80 {
22     delay_loop 6
23     lb_algo wrr
24     lb_kind DR
25     nat_mask 255.255.255.0
26     persistence_timeout 50
27     protocol TCP
28
29     real_server 10.0.0.17 80 {
30         weight 1
31         TCP_CHECK {
32         connect_timeout 8
33         nb_get_retry 3
34         delay_before_retry 3
35         connect_port 80
36         }
37     }
38
39     real_server 10.0.0.18 80 {
40         weight 1
41         TCP_CHECK {
42         connect_timeout 8
43         nb_get_retry 3
44         delay_before_retry 3
45         connect_port 80
46         }
47     }
48 }

 1 ip addr add 10.0.0.13/32 dev lo
 2
 3 cat >>/etc/sysctl.conf<<EOF
 4 net.ipv4.conf.all.arp_ignore = 1
 5 net.ipv4.conf.all.arp_announce = 2
 6 net.ipv4.conf.lo.arp_ignore = 1
 7 net.ipv4.conf.lo.arp_announce = 2
 8 EOF
 9
10 sysctl -p