linux 负载均衡（4层）

浏览数：35 / 时间：2015年06月20日

拓扑
++++++++++++
+ Client + eth0 192.168.1.1/24
++++++++++++
｜
|
++++++++++++ up eth0:192.168.1.254/24
+ GW +
++++++++++++ down eth1:1.1.1.254/24
｜
|
++++++++++++ VIP eth0:1.1.1.1/24
+ Director +
++++++++++++ DIP eth1:172.16.1.254/24
|
___________|____________
| |
| |
++++++++++++ ++++++++++++
+ Real Server A + + Real Server B +
++++++++++++ ++++++++++++
eth0:172.16.1.1/24 eth0:172.16.1.2/24

配置LVS VS/NAT模式
=================================
Client:
[root@localhost ~]# route add default gw 192.168.1.254 dev eth0
设置Client 的网关

GW:
[root@localhost ~]# echo 1 > /proc/sys/net/ipv4/ip_forward
在网关服务器设置开启转发

Real Server A & Real Server B:
[root@localhost ~]# yum install httpd

在两台网站服务器装httpd

A /var/www/html/index.html A的网页zhangyunming1

A /var/www/html/index.html B的网页zhangyunming2

[root@localhost ~]# route add default gw 172.16.1.254 dev eth0
为eth0设置网关

Director:
[root@localhost ~]# echo 1 > /proc/sys/net/ipv4/ip_forward
[root@localhost ~]# route add default gw 1.1.1.254 dev eth0
[root@localhost ~]# yum install ipvsadm

用yum装ipvsadm包
[root@localhost ~]# ipvsadm -A -t 1.1.1.1:80 -s rr
[root@localhost ~]# ipvsadm -a -t 1.1.1.1:80 -r 172.16.1.1:80 -m
[root@localhost ~]# ipvsadm -a -t 1.1.1.1:80 -r 172.16.1.2:80 -m
[root@localhost ~]# ipvsadm -Ln

[root@localhost ~]# ipvsadm -Ln --stat

备注数据包走向
====================================
1.Client---------->GW
sip:CIP dip:VIP
smac:Client_mac dmac:GW_up_mac

2.GW-------------->Director
sip:CIP dip:VIP
smac:GW_down_mac dmac:VIP_mac

3.Director-------->Real Server (DNAT)
sip:CIP dip:RIP
smac:DIP_mac dmac:RealServer_mac

4.Real Server----->Director
sip:RIP dip:CIP
smac:RealServer_mac dmac:DIP_mac

5.Director-------->GW
sip:VIP dip:CIP
smac:VIP_mac dmac:GW_down_mac

6.GW-------------->Client
sip:VIP dip:CIP
smac:GW_up_mac dmac:Client_mac