LVS实现--LVS/NAT模式实现

青旅半醒 2023-07-07 08:04 88阅读 0赞

LVS/NAT原理和特点 ：[https://blog.csdn.net/qq\_35887546/article/details/104425264][https_blog.csdn.net_qq_35887546_article_details_104425264]

**1.实验准备**

本次实验需要三个虚拟机以及物理机：

<table> 
 <thead> 
  <tr> 
   <th>虚拟机名称</th> 
   <th>作用</th> 
   <th>IP</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>server1</td> 
   <td>DS</td> 
   <td>172.25.63.1（内网） ，172.25.254.100（外网）</td> 
  </tr> 
  <tr> 
   <td>server2</td> 
   <td>RS1</td> 
   <td>172.25.63.2</td> 
  </tr> 
  <tr> 
   <td>server3</td> 
   <td>RS2</td> 
   <td>172.25.63.3</td> 
  </tr> 
 </tbody> 
</table>

VIP为：`172.25.254.100`  
测试服务：Http 端口：80  
物理机为客户端

server2与server3安装apache，在默认发布目录/var/www/html下编写发布文件

**2.配置DS**

server1 配置好lvsadm

首先删除之前TUN模式添加的策略，及DR模式时添加的隧道：

[root@server1 ~]# ipvsadm -C
    [root@server1 ~]# ipvsadm -l
    IP Virtual Server version 1.2.1 (size=4096)
    Prot LocalAddress:Port Scheduler Flags
      -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

将之前实验的 ldirectord 和 keepalived 服务停止：

[root@server1 ~]# systemctl stop keepalived
    [root@server1 ~]# systemctl stop ldirectord

删除之前设置的VIP和隧道接口：

[root@server1 ~]# modprobe -r ipip
    [root@server1 ~]# ip addr del 172.25.63.100/32 dev eth0
    [root@server1 ~]# ip addr show
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 52:54:00:1b:f6:56 brd ff:ff:ff:ff:ff:ff
        inet 172.25.63.1/24 brd 172.25.63.255 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::5054:ff:fe1b:f656/64 scope link 
           valid_lft forever preferred_lft forever

**2.为DS添加网卡**

添加网卡，给新网卡添加外网ip：172.25.254.100，并激活网卡  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODg3NTQ2_size_16_color_FFFFFF_t_70]设置ip：

[root@server1 ~]# ip addr add 172.25.63.100/24 dev eth1
    [root@server1 ~]# ip addr show
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 52:54:00:1b:f6:56 brd ff:ff:ff:ff:ff:ff
        inet 172.25.63.1/24 brd 172.25.63.255 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::5054:ff:fe1b:f656/64 scope link 
           valid_lft forever preferred_lft forever
    4: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
        link/ether 52:54:00:5a:47:c7 brd ff:ff:ff:ff:ff:ff
        inet 172.25.63.100/24 scope global eth1
           valid_lft forever preferred_lft forever

激活网卡：

[root@server1 ~]# ip link set up eth1
    [root@server1 ~]# ip addr show
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 52:54:00:1b:f6:56 brd ff:ff:ff:ff:ff:ff
        inet 172.25.63.1/24 brd 172.25.63.255 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::5054:ff:fe1b:f656/64 scope link 
           valid_lft forever preferred_lft forever
    4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 52:54:00:5a:47:c7 brd ff:ff:ff:ff:ff:ff
        inet 172.25.63.100/24 scope global eth1
           valid_lft forever preferred_lft forever
        inet6 fe80::5054:ff:fe5a:47c7/64 scope link 
           valid_lft forever preferred_lft forever

**3.为DS添加NAT模式策略**

在server1：

NAT模式为-m

[root@server1 ~]# ipvsadm -A -t 172.25.254.100:80 -s rr
    [root@server1 ~]# ipvsadm -a -t 172.25.254.100:80 -r 172.25.63.2 -m
    [root@server1 ~]# ipvsadm -a -t 172.25.254.100:80 -r 172.25.63.3 -m
    [root@server1 ~]# ipvsadm -l
    IP Virtual Server version 1.2.1 (size=4096)
    Prot LocalAddress:Port Scheduler Flags
      -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
    TCP  server1:http rr
      -> server2:http                 Masq    1      0          0         
      -> server3:http                 Masq    1      0          0

**4.为DS开启路由机制**  
在server1：

永久开启：

[root@server1 ~]# vim /etc/sysctl.conf 
    填入：
    net.ipv4.ip_forward = 1
    [root@server1 ~]# sysctl -p				#使更改生效
    net.ipv4.ip_forward = 1

临时开启：

sysctl   -a |   grep   ip_forward
    
    sysctl   -w  net.ipv4.ip_forward=1
    
    sysctl   -p

**5.为DS加载nat模块**  
在server1：

[root@server1 ~]# modprobe iptable_nat

注:如果不加载此模块,也可以在第一次访问时成功,但是会在再次访问时出现延迟过长,或访问超时现象

**6.配置RS**

在server2与server3：

先删除server2 与server3 中的tun 模块（以server 2为例，server3 也是同样的操作）：

[root@server2 ~]# modprobe -r ipip
    [root@server2 ~]# ip addr show
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 52:54:00:fb:99:44 brd ff:ff:ff:ff:ff:ff
        inet 172.25.63.2/24 brd 172.25.63.255 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::5054:ff:fefb:9944/64 scope link 
           valid_lft forever preferred_lft forever

给网卡添加网关`172.25.63.1`（以server 2为例，server3 也是同样的操作）：  
永久添加:

[root@server2 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0 
    [root@server2 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
    BOOTPROTO=static
    DEVICE=eth0
    ONBOOT=yes
    IPADDR=172.25.63.2
    PREFIX=24
    GATEWAY=172.25.63.1
    [root@server2 ~]# systemctl restart network				#重启网络
    [root@server2 ~]# route -n
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    0.0.0.0         172.25.63.1     0.0.0.0         UG    0      0        0 eth0				#表示添加成功
    169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0
    172.25.63.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0

临时添加

route   add   default  gw   172.25.63.1          #删除网关：route   del   default  gw   172.25.8.1

**7.测试**

在客户端：

[root@foundation63 ~]# curl 172.25.254.100
    server3
    [root@foundation63 ~]# curl 172.25.254.100
    server2
    [root@foundation63 ~]# curl 172.25.254.100
    server3
    [root@foundation63 ~]# curl 172.25.254.100
    server2
    [root@foundation63 ~]# curl 172.25.254.100
    server3

表示nat模式实现成功

[https_blog.csdn.net_qq_35887546_article_details_104425264]: https://blog.csdn.net/qq_35887546/article/details/104425264
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODg3NTQ2_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200221172637622.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODg3NTQ2,size_16,color_FFFFFF,t_70