一、lvs-nat

1.1 环境信息

角色 IP 网关 Service
director vip(ens37): 172.29.2.69
dip(ens33): 192.168.123.100		 ens37: 172.29.2.1
ens33: 192.168.123.2		 lvs-nat
Real-Server1 rip: 192.168.123.101 192.168.123.100 httpd
Real-Server2 rip: 192.168.123.102 192.168.123.100 httpd

NOTE: 需要打开核心转发功能, “net.ipv4.ip_forward = 1”, 拓扑图参考基础概念中lvs-nat模型图.

1.2 配置步骤

  1. director
$ yum install -y ipvsadm

$ ipvsadm -A -t 172.29.2.60:80 -s rr 
$ ipvsadm -a -t 172.29.2.60:80 -r 192.168.123.101:80 -m
$ ipvsadm -a -t 172.29.2.60:80 -r 192.168.123.102:80 -m

$ ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.29.2.60:80 rr
  -> 192.168.123.101:80           Masq    1      0          0         
  -> 192.168.123.102:80           Masq    1      0          0
  1. Real-server1
$ yum install -y httpd

$ echo -e "web1\n
webserver1\n" > /var/www/html/index.html 
$ cat /var/www/html/index.html
web1

webserver1

$ systemctl start httpd
  1. Real-server2
$ yum install -y httpd

$ echo -e "web2\n
webserver2
\n" > /var/www/html/index.html
$ cat /var/www/html/index.html
web2

webserver2


$ systemct start httpd
  1. 测试: 通过VIP进行访问
$ curl http://172.29.2.60
web2

webserver2


$ curl http://172.29.2.60
web1

webserver1

也可以用浏览器进行访问测试.

  1. 查看连接状态
$ ipvsadm -lnc

二、lvs-dr

2.1 环境信息

角色 IP 网关 service 内核参数
direcotr vip(ens33:0): 192.168.123.110
dip(ens33): 192.168.123.100		 192.168.123.2 lvs-dr \
Real-Server1 vip(lo:0): 192.168.123.110
rip(ens33): 192.168.123.101		 192.168.123.2 httpd arp_ignore = 1
arp_announce=2
Real-Server2 vip(lo:0): 192.168.123.110
rip(ens33): 192.168.123.102		 192.168.123.2 httpd arp_ignore = 1
arp_announce=2
  • arp_ignore:
    • 0: 响应任意网卡上接受到的对本机IP地址的arp请求(包括回环往卡上的地址), 而不管该目的IP是否在接收往卡上
    • 1: 只响应目的IP地址为接收网卡上的本地地址的ARP请求
    • 2: 只响应目的IP地址为接收网卡上的本地地址的ARP请求, 并且arp请求的源IP必须和接收网卡同网段
    • 3: 如果arp请求数据包所请求的IP地址对应的本地地址其作用域(scope)为主机(host), 则不会因arp响应数据包, 如果作用域为全局(global)或链路(link), 则回应arp响应数据包
    • 4~7: 保留未使用
    • 8: 不回应所有的arp请求
  • arp_announce:
    • 允许使用任意网卡IP地址作为arp请求的源IP, 通常就是用数据包的源IP
    • 尽量避免使用不属于该发送网卡子网卡的本地地址作为发送arp请求的源IP地址
    • 忽略IP数据包的源IP地址, 选择该发送网卡上最合适的本地地址作为arp请求的源IP地址

2.2 配置步骤

  1. director
$ ifconfig ens33:0 192.168.123.110/32 broadcast 192.168.123.110 up
$ route add -host 192.168.123.110 dev ens33:0
$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.123.2   0.0.0.0         UG    0      0        0 ens33
169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 ens33
192.168.123.0   0.0.0.0         255.255.255.0   U     0      0        0 ens33
192.168.123.110 0.0.0.0         255.255.255.255 UH    0      0        0 ens33

$ ipvsadm -A -t 192.168.123.110:80 -s rr
$ ipvsadm -a -t 192.168.123.110:80 -r 192.168.123.101 -g
$ ipvsadm -a -t 192.168.123.110:80 -r 192.168.123.102 -g
$ ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.123.110:80 rr
  -> 192.168.123.101:80           Route   1      0          0         
  -> 192.168.123.102:80           Route   1      0          0
  1. Real-Server1
$ echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore 
$ echo 1 > /proc/sys/net/ipv4/conf/ens33/arp_ignore     
$ echo 2 > /proc/sys/net/ipv4/conf/ens33/arp_announce 
$ echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce

$ ifconfig lo:0 192.168.123.110/32 broadcast 192.168.123.110 up
$ route add -host 192.168.123.110 dev lo:0
  1. Real-Server2
$ echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore 
$ echo 1 > /proc/sys/net/ipv4/conf/ens33/arp_ignore     
$ echo 2 > /proc/sys/net/ipv4/conf/ens33/arp_announce 
$ echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce

$ ifconfig lo:0 192.168.123.110/32 broadcast 192.168.123.110 up
$ route add -host 192.168.123.110 dev lo:0