lvs简介
LVS:Linux Virtual Server，负载调度器，内核集成，章文嵩，阿里的四层SLB(Server LoadBalance)是基 于LVS+keepalived实现
lvs集群的类型
lvs-nat： 修改请求报文的目标IP,多目标IP的DNAT
lvs-dr： 操纵封装新的MAC地址 lvs-tun： 在原请求IP报文之外新加一个IP首部
lvs-fullnat： 修改请求报文的源和目标IP
一、lvs的nat模式
lvs是nat模式
[root@lvs ~]# cat /etc/NetworkManager/system-connections/eth1.connection
[connection]
id=eth1
type=ethernet
interface-name=eth1
[ipv4]
address1=192.168.0.100/24
method=manual克隆两个名为webserver1和webserver2，且为仅主机模式
webserver1
[root@webserver1 ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=192.168.0.10/24,192.168.0.100
method=manualwebserver2
[root@webserver2 ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=192.168.0.20/24,192.168.0.100
method=manual网关设不设不影响实验
搭建nat模式
别忘了下载web服务
在webserver里配置
echo webserver1-192.168.0.10 > /var/www/html/index.html
echo webserver1-192.168.0.20 > /var/www/html/index.html 再下载ipvsadm
ipvsadm命令 核心功能: 集群服务管理:增、删、改 集群服务的RS管理:增、删、改 查看
接着配置规则
ipvsadm -A -t 172.25.254.100:80 -s rr
ipvsadm -a -t 172.25.254.100:80 -r 192.168.0.10 -m
ipvsadm -a -t 172.25.254.100:80 -r 192.168.0.20 -m
ipvsadm -Ln
watch -n 1 ipvsadm -Ln --rate测试结果
二、 ipvsadm命令的使用
命令参数
管理集群服务
ipvsadm -A|E -t（tcp）|u（udp）|f（防护墙标签） \
service-address(集群地址) \
[-s scheduler(调度算法)] \
[-p [timeout]] \
[-M netmask] \
[--pepersistence_engine] \
[-b sched-flags]
ipvsadm -D -t|u|f service-address 删除
ipvsadm --C 清空
ipvsadm --R 重载
ipvsadm -S [-n] 保存
管理集群中的real server
ipvsadm -a|e -t|u|f service-address -r server-address [-g | -i| -m](工作模式) [-w
weight](权重)
ipvsadm -d -t|u|f service-address -r server-address 删除RS
ipvsadm -L|l [options] 查看rs
ipvsadm -Z [-t|u|f service-address] 清楚计数器三、lvs的dr模式实现
DR：Direct Routing，直接路由，LVS默认模式,应用最广泛,通过为请求报文重新封装一个MAC首部进行 转发，源MAC是DIP所在的接口的MAC，目标MAC是某挑选出的RS的RIP所在接口的MAC地址；源 IP/PORT，以及目标IP/PORT均保持不变
lvs主机
[root@lvs ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=192.168.0.50/24,192.168.0.100
method=manualwebserver1
[root@server1 ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=192.168.0.10/24,192.168.0.100
method=manualwebserver2
[root@server2 ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=192.168.0.20/24,192.168.0.100
method=manual路由器主机（router）
[root@router ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=172.25.254.100/24,172.25.254.2
dns=114.114.114.114;
method=manual
[root@router ~]# cat /etc/NetworkManager/system-connections/eth1.connection
[connection]
id=eth1
type=ethernet
interface-name=eth1
[ipv4]
address1=192.168.0.100/24
method=manual客户端nat模式（client）
[root@client ~]# cat /etc/NetworkManager/system-connections/eth0.connection
[connection]
id=eth0
type=ethernet
interface-name=eth0
[ipv4]
address1=172.25.254.200/24,172.25.254.100
method=manual之后打开内核路由功能
rs主机中vip不对外响应
在lvs中配置策略
echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore lvs设定：
ipvsadm -A -t 192.168.0.200:80 -s wrr
ipvsadm -a -t 192.168.0.200:80 -r 192.168.0.10:80 -g -w 1
ipvsadm -a -t 192.168.0.200:80 -r 192.168.0.20:80 -g -w 2别忘了启用IP转发
vim /etc/sysctl.conf
net.ipv4.ip_forward = 1
ipvsadm -p在lvs主机和rs主机添加vip
测试效果
[root@client ~]# for N in {1..10};
do
curl 192.168.0.200;
done
RS2 server - 192.168.0.20
RS1 server - 192.168.0.10
RS2 server - 192.168.0.20
RS2 server - 192.168.0.20
RS1 server - 192.168.0.10
RS2 server - 192.168.0.20
RS2 server - 192.168.0.20
RS1 server - 192.168.0.10
RS2 server - 192.168.0.20
RS2 server - 192.168.0.20四、lvs火墙标记
]# yum install mod_ssl -y
]# systemctl restart httpd
[root@lvs ~]# ipvsadm -A -t 192.168.0.100:80 -s rr
[root@lvs ~]# ipvsadm -A -t 192.168.0.100:443 -s rr
[root@lvs ~]# ipvsadm -a -t 192.168.0.100:80 -r 192.168.0.101:80 -g
[root@lvs ~]# ipvsadm -a -t 192.168.0.100:80 -r 192.168.0.102:80 -g
[root@lvs ~]# ipvsadm -a -t 192.168.0.100:443 -r 192.168.0.102:80 -g
[root@lvs ~]# ipvsadm -a -t 192.168.0.100:443 -r 192.168.0.101:80 -g测试
[root@node10 ~]# curl http://192.168.0.100;curl -k https://192.168.0.100
RS1 server - 192.168.0.101
RS1 server - 192.168.0.101