注释 Dialer Watch通过跟踪路由表中特定路由前缀得存在情况来判断是否需要触发拨号，这里要特别注意得是例子中监控了两个路由前缀，必须两个路由前缀都消失才会触发拨号。还是建议使用13.1中得浮动路由方式来进行拨号备份
13.6. 使用Virtual Templates
提问 使用Virtual Templates得方式来配置拨号备份
回答
dialhost#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
dialhost(config)#username Router1 password dialpassword
dialhost(config)#interface BRI0/0
dialhost(config-if)#no ip address
dialhost(config-if)#encapsulation ppp
dialhost(config-if)#dialer pool-member 1
dialhost(config-if)#isdn switch-type basic-ni
dialhost(config-if)#isdn point-to-point-setup
dialhost(config-if)#isdn spid1 800555123400 5551234
dialhost(config-if)#isdn spid2 800555123500 5551235
dialhost(config-if)#ppp authentication chap
dialhost(config-if)#ppp multilink
dialhost(config-if)#exit
dialhost(config)#interface Dialer1
dialhost(config-if)#no ip address
dialhost(config-if)#encapsulation ppp
dialhost(config-if)#dialer idle-timeout 300
dialhost(config-if)#dialer-group 1
dialhost(config-if)#no peer default ip address
dialhost(config-if)#ppp authentication chap
dialhost(config-if)#ppp multilink
dialhost(config-if)#exit
dialhost(config)#access-list 101 deny eigrp any any
dialhost(config)#access-list 101 permit ip any any
dialhost(config)#dialer-list 1 protocol ip list 101
dialhost(config)#router eigrp 55
dialhost(config-router)#network 10.0.0.0
dialhost(config-router)#exit
dialhost(config)#interface Loopback1
dialhost(config-if)#ip address 10.1.99.1 255.255.255.0
dialhost(config-if)#exit
dialhost(config)#interface Virtual-Template1
dialhost(config-if)#ip unnumbered Loopback1
dialhost(config-if)#encapsulation ppp
dialhost(config-if)#ppp authentication chap
dialhost(config-if)#ppp multilink
dialhost(config-if)#ppp multilink load-threshold 50 either
dialhost(config-if)#exit
dialhost(config)#virtual-profile virtual-template 1
dialhost(config)#end
dialhost#注释 一般用于中心得拨号服务器，类似于13.2但是在Dialer 接口下也没有配置IP地址，而是配置在Virtual Template上
13.7. 确保断线正常
提问 当主链路恢复以后确保备份链路断线正常
回答
Router1#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router1(config)#interface Serial0/0.1 point-to-point
Router1(config-subif)#bandwidth 56
Router1(config-subif)#exit
Router1(config)#interface BRI0/0
Router1(config-subif)#bandwidth 54
Router1(config-subif)#end
Router1#注释 通过配置带宽得方式来调整主备接口得metric值，从而避免在路由计算时选用备份接口
13.8. 查看拨号备份状态
提问 查看拨号备份状态
回答
Router1#show dialer
Router1#show backup
Router1#show isdn status
Router1#show isdn active
Router1#show isdn history注释 show dialer里面比较有意思得信息是Dial reason: ip (s=10.1.99.55, d=224.0.0.10)，从而确定是什么数据触发得拨号
<!--[if !supportLists]-->13.9. <!--[endif]-->拨号备份排错
提问 查找拨号备份失败原因
回答
Router1#debug ppp authentication
Router1#debug dialer更多内容请看PCdog.com--Cisco IOS技术手册 Cisco交换机 Cisco路由器配置手册专题
