配置思路如下,出口路由器把DNS服务器端口映射到LB,由LB来做DNS应答
LB重要配置如下
[LB] interface gigabitethernet 1/0/1
[LB-GigabitEthernet1/0/1] ip address 10.1.1.1 24 //LB内网地址
[LB] loadbalance link link_chinatel
[LB-lb-link-link1] router ip 152.52.52.x //电信的链路的下一跳地址
[LB] loadbalance link link_unicom
[LB-lb-link-link1] router ip 143.43.43.x //联通的链路的下一跳地址
[LB] virtual-server vs_chinatel type tcp
只用作dns解析的话,请使用tcp类型虚服务便可,不需要http类型,虚服务只用于dns映射的配置需要,service可以不用开启
[LB-vs-http-vs1] virtual ip address 152.52.52.1 24
[LB-vs-http-vs1] port 80
[LB-vs-http-vs1] default server-farm sf
[LB-vs-http-vs1] undo service enable
[LB] virtual-server vs_unicom type tcp
[LB-vs-http-vs2] virtual ip address 143.43.43.1 24
[LB-vs-http-vs2] port 80
[LB-vs-http-vs2] default server-farm sf
[LB-vs-http-vs2] undo service enable
[LB] loadbalance virtual-server-pool vsp //创建vspool
[LB-lb-vspool-vsp] virtual-server vs_chinatel link link_chinatel //绑定链路和虚服务的关系
[LB-lb-vspool-vsp] virtual-server vs_unicom link link_unicom
[LB-lb-vspool-vsp]predictor preferred topology //配置算法为topo
还需要配置topo如下配置:
[LB]topology region chinatel ip 152.52.52.1
[LB]topology region unicom ip 143.43.43.1
[LB]loadbalance region chinatel //配置region与isp表项绑定
[LB-lb-region-chinatel]isp chinatel
[LB]loadbalance region unicom
[LB-lb-region-unicom]isp cnc
[LB] loadbalance dns-listener dl1 //设置DNS监听器
[LB-lb-dl-dl1] ip address 10.1.1.1
[LB-lb-dl-dl1] service enable
[LB-lb-dl-dl1] quit
[LB] loadbalance dns-map dm //配置dns映射
[LB-lb-dm-dm] domain-name ***.*** //需要解析的域名
[LB-lb-dm-dm] service enable
[LB-lb-dm-dm] virtual-server-pool vsp //设置对应的vspool
[LB-lb-dm-dm] quit
LB响应DNS后,解析出来的地址直接在出口路由器上做映射到内网服务器
业务流量不经过LB