LVS跨网段DR模型配置

喜欢ヅ旅行 2021-10-23 10:55 299阅读 0赞

本次试验使用 5台 VMware 虚拟机搭建，Client 和 Router ens33网卡设置为桥接模式，其余网卡均为主机模式，各 ip 地址 规划如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjU5NTAxMg_size_16_color_FFFFFF_t_70][]

### **一、各主机网络配置文件如下：** ###

**1.Client**

[root@Client ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33 
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=6.6.6.6
    NETMASK=255.255.255.0
    GATEWAY=6.6.6.1
    NAME=ens33
    DEVICE=ens33
    ONBOOT=yes

[root@Client ~]# ifconfig
    ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 6.6.6.6  netmask 255.255.255.0  broadcast 6.6.6.255
            inet6 fe80::20c:29ff:feec:ed4f  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:ec:ed:4f  txqueuelen 1000  (Ethernet)
            RX packets 4148  bytes 282249 (275.6 KiB)
            RX errors 0  dropped 1  overruns 0  frame 0
            TX packets 441  bytes 77912 (76.0 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 968  bytes 77720 (75.8 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 968  bytes 77720 (75.8 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

**2.Router**

[root@Router ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=6.6.6.1
    NETMASK=255.255.255.0
    NAME=ens33
    DEVICE=ens33
    ONBOOT=yes
    [root@Router ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens37
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=192.168.0.1
    NETMASK=255.255.255.0
    NAME=ens37
    DEVICE=ens37
    ONBOOT=yes
    [root@Router ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens37:0
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=9.9.9.1
    NETMASK=255.255.255.0
    NAME=ens37:0
    DEVICE=ens37:0
    ONBOOT=yes

[root@Router ~]# ifconfig
    ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 6.6.6.1  netmask 255.255.255.0  broadcast 6.6.6.255
            inet6 fe80::20c:29ff:fe49:d145  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:49:d1:45  txqueuelen 1000  (Ethernet)
            RX packets 2742  bytes 185080 (180.7 KiB)
            RX errors 0  dropped 1  overruns 0  frame 0
            TX packets 215  bytes 21219 (20.7 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    ens37: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.0.1  netmask 255.255.255.0  broadcast 192.168.0.255
            inet6 fe80::20c:29ff:fe49:d14f  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:49:d1:4f  txqueuelen 1000  (Ethernet)
            RX packets 2  bytes 303 (303.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 31  bytes 2358 (2.3 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    ens37:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 9.9.9.1  netmask 255.255.255.0  broadcast 9.9.9.255
            ether 00:0c:29:49:d1:4f  txqueuelen 1000  (Ethernet)
    
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 0  bytes 0 (0.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 0  bytes 0 (0.0 B)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

**3.LVS**

[root@LVS ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=192.168.0.10
    NETMASK=255.255.255.0
    GATEWAY=192.168.0.1
    NAME=ens33
    DEVICE=ens33
    ONBOOT=yes
    [root@LVS ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33:0
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=9.9.9.9
    NETMASK=255.255.255.0
    NAME=ens33:0
    DEVICE=ens33:0
    ONBOOT=yes

[root@LVS ~]# ifconfig
    ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.0.10  netmask 255.255.255.0  broadcast 192.168.0.255
            inet6 fe80::20c:29ff:feb8:7164  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:b8:71:64  txqueuelen 1000  (Ethernet)
            RX packets 182727  bytes 11437766 (10.9 MiB)
            RX errors 0  dropped 64  overruns 0  frame 0
            TX packets 10919  bytes 940289 (918.2 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    ens33:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 9.9.9.9  netmask 255.255.255.0  broadcast 9.9.9.255
            ether 00:0c:29:b8:71:64  txqueuelen 1000  (Ethernet)
    
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 2683  bytes 217652 (212.5 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 2683  bytes 217652 (212.5 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

**4.RS01**

**在RS服务器的还回口上配置vip之前，应先修改内核arp参数，禁止RS发出arp广播以及arp响应报文：**

**修改结果如下：**

[root@RS01 ~]# cat /proc/sys/net/ipv4/conf/all/arp_ignore
    1
    [root@RS01 ~]# cat /proc/sys/net/ipv4/conf/lo/arp_ignore
    1
    [root@RS01 ~]# cat /proc/sys/net/ipv4/conf/all/arp_announce
    2
    [root@RS01 ~]# cat /proc/sys/net/ipv4/conf/lo/arp_announce 
    2

[root@RS01 ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33    
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=192.168.0.11
    NETMASK=255.255.255.0
    GATEWAY=192.168.0.1
    NAME=ens33
    DEVICE=ens33
    ONBOOT=yes
    [root@RS01 ~]# cat /etc/sysconfig/network-scripts/ifcfg-lo:0
    DEVICE=lo:0
    NAME=lo:0
    IPADDR=9.9.9.9
    NETMASK=255.255.255.255
    ONBOOT=yes

[root@RS01 ~]# ifconfig
    ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.0.11  netmask 255.255.255.0  broadcast 192.168.0.255
            inet6 fe80::20c:29ff:fe3a:5119  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:3a:51:19  txqueuelen 1000  (Ethernet)
            RX packets 4304  bytes 354474 (346.1 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 2859  bytes 407104 (397.5 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 596  bytes 47240 (46.1 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 596  bytes 47240 (46.1 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 9.9.9.9  netmask 255.255.255.255
            loop  txqueuelen 1000  (Local Loopback)

**5.RS02**

[root@RS02 ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
    TYPE=Ethernet
    BOOTPROTO=none
    IPADDR=192.168.0.12
    NETMASK=255.255.255.0
    GATEWAY=192.168.0.1
    NAME=ens33
    DEVICE=ens33
    ONBOOT=yes
    [root@RS02 ~]# cat /etc/sysconfig/network-scripts/ifcfg-lo:0 
    DEVICE=lo:0
    NAME=lo:0
    IPADDR=9.9.9.9
    NETMASK=255.255.255.255
    ONBOOT=yes

[root@RS02 ~]# ifconfig
    ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.0.12  netmask 255.255.255.0  broadcast 192.168.0.255
            inet6 fe80::20c:29ff:fedb:a51a  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:db:a5:1a  txqueuelen 1000  (Ethernet)
            RX packets 6266  bytes 514451 (502.3 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 3910  bytes 535357 (522.8 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 1454  bytes 118913 (116.1 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 1454  bytes 118913 (116.1 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 9.9.9.9  netmask 255.255.255.255
            loop  txqueuelen 1000  (Local Loopback)

**6.网络连通性测试**

在客户端 ping vip(9.9.9.9)

[root@Client ~]# ping -c 3 9.9.9.9
    PING 9.9.9.9 (9.9.9.9) 56(84) bytes of data.
    64 bytes from 9.9.9.9: icmp_seq=1 ttl=64 time=3.57 ms
    64 bytes from 9.9.9.9: icmp_seq=2 ttl=64 time=0.834 ms
    64 bytes from 9.9.9.9: icmp_seq=3 ttl=64 time=0.839 ms
    
    --- 9.9.9.9 ping statistics ---
    3 packets transmitted, 3 received, 0% packet loss, time 2012ms
    rtt min/avg/max/mdev = 0.834/1.748/3.572/1.289 ms

在RS上 ping 客户端

[root@RS01 ~]# ping -c 3 6.6.6.6
    PING 6.6.6.6 (6.6.6.6) 56(84) bytes of data.
    64 bytes from 6.6.6.6: icmp_seq=1 ttl=63 time=1.98 ms
    64 bytes from 6.6.6.6: icmp_seq=2 ttl=63 time=1.25 ms
    64 bytes from 6.6.6.6: icmp_seq=3 ttl=63 time=1.42 ms
    
    --- 6.6.6.6 ping statistics ---
    3 packets transmitted, 3 received, 0% packet loss, time 2028ms
    rtt min/avg/max/mdev = 1.258/1.555/1.980/0.311 ms

--------------------

### 二、在RS上安装httpd ###

[root@LVS ~]# curl 192.168.0.11
    RS01
    [root@LVS ~]# curl 192.168.0.12
    RS02

### 三、设置LVS调度规则 ###

1.安装ipvsadm

[root@LVS ~]# yum install ipvsadm -y

2.设置lvs规则

[root@LVS ~]# ipvsadm -A -t 9.9.9.9:80 -s rr           
    [root@LVS ~]# ipvsadm -a -t 9.9.9.9:80 -r 192.168.0.11:80 -g           
    [root@LVS ~]# ipvsadm -a -t 9.9.9.9:80 -r 192.168.0.12:80 -g 
    [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  9.9.9.9:80 rr
      -> 192.168.0.11:80              Route   1      0          0         
      -> 192.168.0.12:80              Route   1      0          0

### 四、LVS调度测试 ###

**1.在LVS上访问测试**

[root@LVS ~]# curl 9.9.9.9
    ^C

结果：长时间无反应，

**2.在client端访问测试**

[root@Client ~]# curl 9.9.9.9
    RS01
    [root@Client ~]# curl 9.9.9.9
    RS02
    [root@Client ~]# curl 9.9.9.9
    RS01
    [root@Client ~]# curl 9.9.9.9
    RS02

LVS调度成功，工作正常！

### **五、LVS工作原理** ###

在上面的调度测试中，为何在LVS上测试时长时间无反应？

LVS 的 IP 负载均衡技术是通过 ipvs 模块来实现的，ipvs 是 LVS 集群系统的核心软件，ipvs 工作于内核空间的 INPUT 链上。

当收到用户请求某集群服务时，经过 PREROUTING 链，经检查本机路由表，送往 INPUT 链；在进入 netfilter 的 INPUT 链时，ipvs 强行将请求报文通过 ipvsadm 定义的集群服务策略的路径改为 FORWORD 链，将报文转发至后端真实提供服务的主机。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjU5NTAxMg_size_16_color_FFFFFF_t_70 1][]

所以在 LVS 上测试时，本机发出的请求，是直接从 OUTPUT 链流向 POSTROUTING 链，不会经由INPUT链，所以不会经过 ipvs 调度规则，因此长时间无反应。

### 六、设置LVS规则开机自动加载 ###

将 ipvs 规则写进 /etc/sysconfig/ipvsadm 文件，到服务器宕机重启后，会自动加载。

ipvs 服务默认启动停止策略如下：

[root@LVS ~]# cat /usr/lib/systemd/system/ipvsadm.service
    [Unit]
    Description=Initialise the Linux Virtual Server
    After=syslog.target network.target
    
    [Service]
    Type=oneshot
    ExecStart=/bin/bash -c "exec /sbin/ipvsadm-restore < /etc/sysconfig/ipvsadm"
    ExecStop=/bin/bash -c "exec /sbin/ipvsadm-save -n > /etc/sysconfig/ipvsadm"
    ExecStop=/sbin/ipvsadm -C
    RemainAfterExit=yes
    
    [Install]
    WantedBy=multi-user.target

保存当前规则到文件：

[root@LVS ~]# ipvsadm-save -n > /etc/sysconfig/ipvsadm

从文件中加载策略：

[root@LVS ~]# ipvsadm-restore < /etc/sysconfig/ipvsadm

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