LVS NAT模型配置示例

1、LVS-NAT基于Cisco的LocalDirector。VS/NAT不需要在RealServer上做任何设置，其只要能提供一个tcp/ip的协议栈即可，甚至其无论基于什么OS。

2、基于VS/NAT，所有的入站数据包均由Director进行目标地址转换后转发至内部的RealServer，RealServer响应的数据包再由Director转换源地址后发回客户端。

3、VS/NAT模式不能与netfilter兼容，因此，不能将VS/NAT模式的Director运行在netfilter的保护范围之中。

# 注意：各节点间的时间偏差不应该超出1秒钟。

# Director配置NTP服务器：

Director：

yum install ntp

/etc/init.d/ntpd start

Client：

/usr/sbin/ntpdate Director_IP

VS/NAT拓扑示例：

Client

CIP=192.168.101.253

|

|

VIP=192.168.101.168 (eth0)

Director

DIP=10.10.10.1 (eth1)

|

(switch) ——————————

|                                            |

RIP=10.10.10.11 (eth0)        RIP=10.10.10.12 (eth0)

RS1                                      RS2

VS/NAT配置示例：

Director IP：

VIP：192.168.101.168/24

DIP：10.10.10.1/24

RS1 IP：

RIP：10.10.10.11/24    gw:10.10.10.1

RS2 IP：

RIP：10.10.10.12/24    gw:10.10.10.1

1、Director安装ipvsadm

# yum install ipvsadm

2、RS1安装httpd

# yum install httpd

# echo "rs1.redhat.com" > /var/www/html/index.html

# service httpd start

3、RS2安装httpd

# yum install httpd

# echo "rs2.redhat.com" > /var/www/html/index.html

# service httpd start

4、Director配置集群（调度算法：RR）

# echo 1 > /proc/sys/net/ipv4/ip_forward

# ipvsadm -A -t 192.168.101.168:80 -s rr

# ipvsadm -a -t 192.168.101.168:80 -r 10.10.10.11 -m

# ipvsadm -a -t 192.168.101.168:80 -r 10.10.10.12 -m

# ipvsadm -L -n

5、浏览器访问：http://192.168.101.168

6、Director配置集群（调度算法：WRR）

# ipvsadm -E -t 192.168.101.168:80 -s wrr

# ipvsadm -e -t 192.168.101.168:80 -r 10.10.10.11 -m -w 3

# ipvsadm -e -t 192.168.101.168:80 -r 10.10.10.12 -m -w 1

# ipvsadm -L -n --stats

7、浏览器访问：http://192.168.101.168

8、保存规则

# service ipvsadm save

或者：

# ipvsadm -S > /etc/sysconfig/ipvsadm.web

VS/NAT Script：

#!/bin/bash

#

# chkconfig: - 88 12

# description: LVS Script for VS/NAT.

#

. /etc/rc.d/init.d/functions

VIP=192.168.101.168

DIP=10.10.10.1

RIP1=10.10.10.11

RIP2=10.10.10.12

CSTATUS1() {

[ -e /var/lock/subsys/ipvsadm.lock ] && echo -e "\033[32mipvsadm is running...\033[0m" && exit 1

}

CSTATUS2() {

[ ! -e /var/lock/subsys/ipvsadm.lock ] && echo -e "\033[32mipvsadm is not running...\033[0m" && exit 2

}

case "$1" in

start)

CSTATUS1

echo -e "\033[32mStart VS/NAT of Director Server...\033[0m"

# Set the Virtual IP address.

/sbin/ifconfig eth0 $VIP netmask 255.255.255.0 up

/sbin/ifconfig eth1 $DIP netmask 255.255.255.0 up

# Director must open packet forwarding.

echo 1 > /proc/sys/net/ipv4/ip_forward

# Clean all iptables rules.

/sbin/iptables -F

# Reset iptables counters.

/sbin/iptables -Z

# Clean all ipvsadm rules/services.

/sbin/ipvsadm -C

# Set VS/NAT, Scheduling is Round Robin.

/sbin/ipvsadm -A -t $VIP:80 -s rr

/sbin/ipvsadm -a -t $VIP:80 -r $RIP1 -m

/sbin/ipvsadm -a -t $VIP:80 -r $RIP2 -m

# Show VS/NAT status.

/sbin/ipvsadm -L -n

/bin/touch /var/lock/subsys/ipvsadm.lock

;;

stop)

CSTATUS2

echo -e "\033[32mStop VS/NAT of Director Server...\033[0m"

# Reset ipvsadm.

/sbin/ipvsadm -C

# Close VIP interface.

/sbin/ifconfig eth0 down &> /dev/null

# Close packet forwarding.

echo 0 > /proc/sys/net/ipv4/ip_forward

/bin/rm -f /var/lock/subsys/ipvsadm.lock

;;

status)

[ -e /var/lock/subsys/ipvsadm.lock ] && echo -e "\033[32mipvsadm is running...\033[0m" || echo -e "\033[32mipvsadm is not running...\033[0m"

;;

*)

echo -e "\033[32mUsage: $0 {start|stop|status}\033[0m"

;;

esac