LVS负载均衡集群部署之—NAT模式的介绍及搭建步骤

一、环境准备

1.准备三台rhel9服务器

服务器名称	主机名	ip地址	备注
LVS调度服务器	lvs.timinglee.org	eth0:172.25.254.100（外网） eth1:192.168.0.100(内网)	关闭selinux和防火墙
webserver2网站服务器	webserver1.timinglee.org	eth0：192.168.0.10（内网）	关闭selinux和防火墙
webserver2网站服务器	webserver2.timinglee.org	eth0：192.168.0.20（内网）	关闭selinux和防火墙

2.实验拓扑

二、LVS-NAT模式部署

# 版本
[root@lvs ~]# hostnamectl Static hostname: lvs.timinglee.orgIcon name: computer-vmChassis: vm ??Machine ID: 4748448370474b72a05bc780ede57860Boot ID: de3da80744f044728475c9c7388a2f1cVirtualization: vmware
Operating System: Red Hat Enterprise Linux 9.1 (Plow)     CPE OS Name: cpe:/o:redhat:enterprise_linux:9::baseosKernel: Linux 5.14.0-162.6.1.el9_1.x86_64Architecture: x86-64Hardware Vendor: VMware, Inc.Hardware Model: VMware Virtual Platform

# lvs主机网卡配置
[root@lvs ~]# cat /etc/NetworkManager/system-connections/eth0.nmconnection 
[connection]
id=eth0
type=ethernet
interface-name=eth0[ipv4]
address1=172.25.254.100/24,172.25.254.2
method=manual
dns=114.114.114.114;
[root@lvs ~]# cat /etc/NetworkManager/system-connections/eth1.nmconnection 
[connection]
id=eth1
type=ethernet
interface-name=eth1[ipv4]
address1=192.168.0.100/24
method=manualwebserver1网卡配置，配置网关
[root@webserver1 ~]# cat /etc/NetworkManager/system-connections/eth0.nmconnection 
[connection]
id=eth0
type=ethernet
interface-name=eth0[ipv4]
address1=192.168.0.10/24,192.168.0.100
method=manual
dns=114.114.114.114;webserver2网卡配置，配置网关
[root@webserver2 ~]# cat /etc/NetworkManager/system-connections/eth0.nmconnection 
[connection]
id=eth0
type=ethernet
interface-name=eth0[ipv4]
address1=192.168.0.20/24,192.168.0.100
method=manual
dns=114.114.114.114;

 1.给webserver1，webserver2服务器安装httpd

[root@webserver1 ~]# yum install httpd -y
[root@webserver1 ~]# echo webserver1 - 192.168.0.10 > /var/www/html/index.html
[root@webserver1 ~]# systemctl enable --now httpd
Created symlink /etc/systemd/system/multi-user.target.wants/httpd.service → /usr/lib/systemd/system/httpd.service.[root@webserver2 ~]# yum install httpd -y
[root@webserver2 ~]# echo webserver1 - 192.168.0.20 > /var/www/html/index.html
[root@webserver2 ~]# systemctl enable --now httpd
Created symlink /etc/systemd/system/multi-user.target.wants/httpd.service → /usr/lib/systemd/system/httpd.service.

2.在LVS服务器中检测

[root@lvs ~]# ipvsadm -A -t ^C
[root@lvs ~]# curl 192.168.0.10
webserver1 - 192.168.0.10
[root@lvs ~]# curl 192.168.0.20
webserver2 - 192.168.0.20

 3.在LVS服务器中安装LVS

[root@lvs ~]# yum install ipvsadm.x86_64 -y

 4.新建LVS集群

[root@lvs ~]# ipvsadm -A -t 172.25.254.100:80 -s rr
[root@lvs ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.25.254.100:80 rr

5.添加Real Server服务器节点

-a     添加真实服务器
-d     删除真实服务器
-r     指定真实服务器（Real Server）的地址
-m     使用NAT模式；另外 -g 对应DR模式、-i 对应TUN模式
-w     为节点服务器设置权重，默认为1，只有设置加权轮询或者加权最小连接才生效#将两个web服务器加入LVS集群，-m表示为NAT模式[root@lvs ~]# ipvsadm -a -t 172.25.254.100:80 -r 192.168.0.10:80 -m
[root@lvs ~]# ipvsadm -a -t 172.25.254.100:80 -r 192.168.0.20:80 -m
[root@lvs ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.25.254.100:80 rr-> 192.168.0.10:80              Masq    1      0          0         -> 192.168.0.20:80              Masq    1      0          0         
[root@lvs ~]# #补充：如果想删除节点，将-a换成-d即可

6.开启路由转发模式

因为LVS的工作原理是路由转发，所以LVS调度服务器需要开启路由转发[root@lvs ~]# sysctl -a | grep ip_forward
net.ipv4.ip_forward = 0
net.ipv4.ip_forward_update_priority = 1
net.ipv4.ip_forward_use_pmtu = 0[root@lvs ~]# cat /etc/sysctl.conf 
# 定位最后一行添加
net.ipv4.ip_forward = 1# 生效
[root@lvs ~]# sysctl -p
net.ipv4.ip_forward = 1

7.效果测试

[root@lvs ~]# curl 172.25.254.100
web2 - 192.168.0.20
[root@lvs ~]# curl 172.25.254.100
web1 - 192.168.0.10
[root@lvs ~]# 
[root@lvs ~]# for i in {1..10}
> do
> curl 172.25.254.100
> done
web2 - 192.168.0.20
web1 - 192.168.0.10
web2 - 192.168.0.20
web1 - 192.168.0.10
web2 - 192.168.0.20
web1 - 192.168.0.10
web2 - 192.168.0.20
web1 - 192.168.0.10
web2 - 192.168.0.20
web1 - 192.168.0.10

如上可以看到轮询负载均衡效果！！！