LVS小试（RHEL5.4）

[b][size=medium][color=darkblue]1.LVS/NAT[/color][/size][/b]
原理：

客户端—>LVS外网IP（VIP）—>RS服务器（处理请求后通过网关返回结果）—>LVS的LB地址—>客户端

配置LVS/NAT模式时外网IP不要和LoadBalance（LB）的IP同一网段（使用VMWare时两个网卡不要设置同一网段，可以一个是NAT一个是HOST）

LVS外网IP：192.168.142.131
LVS_LB的IP：192.168.254.128
RS_1：192.168.254.129 GW 192.168.254.128
RS_2：192.168.254.130 GW 192.168.254.128

配置LVS：

iptables -F
echo "1">/proc/sys/net/ipv4/ip_forward
ipvsadm -C
ipvsadm -A -t 192.168.142.131:80 -s rr
ipvsadm -a -t 192.168.142.131:80 -r 192.168.254.129 -m -w 1
ipvsadm -a -t 192.168.142.131:80 -r 192.168.254.130 -m -w 1

LVS的网卡信息大约如下：

eth0      Link encap:Ethernet  HWaddr 00:0C:29:76:38:6B  
          inet addr:192.168.142.131  Bcast:192.168.142.255  Mask:255.255.255.0
          ......

eth1      Link encap:Ethernet  HWaddr 00:0C:29:76:38:75  
          inet addr:192.168.254.128  Bcast:192.168.254.255  Mask:255.255.255.0
          ......

配置RS，其实RS的配置就只需要设置网关：
RS_1：

vi /etc/sysconfig/network-scripts/ifcfg-eth0
        DEVICE=eth0
        BOOTPROTO=static
        ONBOOT=yes
        HWADDR=00:0c:29:3d:fe:c5
        IPADDR=192.168.254.129
        NETMASK=255.255.255.0
        GATEWAY=192.168.254.128
service network restart
cd /var/www/html/
echo "129">index.html
apachectl start
iptables -F

RS_2：

vi /etc/sysconfig/network-scripts/ifcfg-eth0
        DEVICE=eth0
        BOOTPROTO=static
        ONBOOT=yes
        HWADDR=00:0c:29:3d:fe:c5
        IPADDR=192.168.254.130
        NETMASK=255.255.255.0
        GATEWAY=192.168.254.128
service network restart
cd /var/www/html/
echo "130">index.html
apachectl start
iptables -F

[b][size=medium][color=darkblue]2.LVS/DR[/color][/size][/b]
原理：

客户端—>LVS的VIP—>RS服务器（处理请求后直接返回结果给客户端）—>客户端

LVS端的网卡需要有一个IP地址段与RS同一网段

LVS的IP：192.168.254.128
LVS的VIP：192.168.254.100
RS_1的IP：192.168.254.129
RS_1的VIP（lo:0）：192.168.254.100
RS_2的IP：192.168.254.130
RS_2的VIP（lo:0）：192.168.254.100

配置LVS：

vi /etc/sysctl.conf 
        # Controls IP packet forwarding
        net.ipv4.ip_forward = 1
        net.ipv4.conf.all.send_redirects = 1
        net.ipv4.conf.default.send_redirects = 1
        net.ipv4.conf.eth1.send_redirects = 1
sysctl -p
ifconfig eth1:0 192.168.254.100 netmask 255.255.255.255 broadcast 192.168.254.100 up
route add -host 192.168.254.100 dev eth1:0
ipvsadm -C
ipvsadm -A -t 192.168.254.100:80 -s rr
ipvsadm -a -t 192.168.254.100:80 -r 192.168.254.129 -g -w 1
ipvsadm -a -t 192.168.254.100:80 -r 192.168.254.130 -g -w 1
iptables -F

配置RS_1：

 vi /etc/sysctl.conf 
         # Controls IP packet forwarding
        net.ipv4.ip_forward = 0
        net.ipv4.conf.lo.arp_ignore = 1
        net.ipv4.conf.lo.arp_announce = 2
        net.ipv4.conf.all.arp_ignore = 1
        net.ipv4.conf.all.arp_announce = 2
sysctl -p
ifconfig lo:0 192.168.254.100 netmask 255.255.255.255 broadcast 192.168.254.100 up
route add -host 192.168.254.100 dev lo:0
cd /var/www/html/
echo "129">index.html
apachectl start
 iptables -F

配置RS_2：

   vi /etc/sysctl.conf 
        # Controls IP packet forwarding
        net.ipv4.ip_forward = 0
        net.ipv4.conf.lo.arp_ignore = 1
        net.ipv4.conf.lo.arp_announce = 2
        net.ipv4.conf.all.arp_ignore = 1
        net.ipv4.conf.all.arp_announce = 2
   sysctl -p
   ifconfig lo:0 192.168.254.100 netmask 255.255.255.255 broadcast 192.168.254.100 up
   route add -host 192.168.254.100 dev lo:0
   cd /var/www/html/
   echo "130">index.html
   apachectl start
   iptables -F

[b][size=medium][color=darkblue]3.LVS/TUN[/color][/size][/b]
原理：

客户端—>LVS的VIP（通过IP Tunneling）—>RS服务器（处理请求后直接返回结果给客户端）—>客户端

RS服务器需要与外网直接通信

LVS的IP：192.168.254.128
LVS的VIP：192.168.254.100
RS_1的IP：192.168.254.129
RS_1的TUN IP（tunl0）：192.168.254.100
RS_2的IP：192.168.254.129
RS_2的TUN IP（tunl0）：192.168.254.100

配置LVS：

  iptables -F
  echo "0">/proc/sys/net/ipv4/ip_forward 
  ifconfig eth1:0 192.168.254.100 netmask 255.255.255.255 broadcast 192.168.254.100 up
  route add -host 192.168.254.100 dev eth1:0
  ipvsadm -C
  ipvsadm -A -t 192.168.254.100:80 -s rr
  ipvsadm -a -t 192.168.254.100:80 -r 192.168.254.129 -i -w 1
  ipvsadm -a -t 192.168.254.100:80 -r 192.168.254.130 -i -w 1

配置RS_1：

  iptables -F
  ifconfig tunl0 192.168.254.100 netmask 255.255.255.255 broadcast 192.168.254.100 up
  route add -host 192.168.254.100 dev tunl0
  cd /var/www/html/
  echo "129">index.html
  apachectl start

配置RS_2：

  iptables -F
  ifconfig tunl0 192.168.254.100 netmask 255.255.255.255 broadcast 192.168.254.100 up
  route add -host 192.168.254.100 dev tunl0
  cd /var/www/html/
  echo "130">index.html
  apachectl start