Cisco IOS Cookbook 中文精简版第十三章拨号备份

wade2007

13.1.  自动拨号备份

提问 当广域网链路中断得时候自动拨号恢复备份链路

回答

Router1#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router1(config)#interface BRI0/0

Router1(config-if)#ip address 10.1.99.55 255.255.255.0

Router1(config-if)#encapsulation ppp

Router1(config-if)#dialer idle-timeout 300

Router1(config-if)#dialer map ip 10.1.99.1 name dialhost broadcast 95551212

Router1(config-if)#dialer load-threshold 50 either

Router1(config-if)#dialer-group 1

Router1(config-if)#isdn switch-type basic-ni

Router1(config-if)#isdn spid1 800555123400 5551234

Router1(config-if)#isdn spid2 800555123500 5551235

Router1(config-if)#ppp authentication chap

Router1(config-if)#ppp multilink

Router1(config-if)#exit

Router1(config)#username dialhost password dialpassword

Router1(config)#ip route 0.0.0.0 0.0.0.0 10.1.99.1 180

Router1(config)#dialer-list 1 protocol ip list 101

Router1(config)#access-list 101 deny eigrp any any

Router1(config)#access-list 101 permit ip any any

Router1(config)#router eigrp 55

Router1(config-router)#network 10.0.0.0

Router1(config-router)#end

Router1#

注释 isdn switch-type 定义对端ISDN交换机类型，中国用basic-net3。通过Router1#show isdn status 来查看当前状态

Router1#show isdn status

Global ISDN Switchtype = basic-ni

ISDN BRI1/0 interface

    dsl 8, interface ISDN Switchtype = basic-ni

    Layer 1 Status:

    ACTIVE

    Layer 2 Status:

    TEI = 85, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

    TEI = 86, Ces = 2, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

    TEI 85, ces = 1, state = 8(established)

        spid1 configured, spid1 sent, spid1 valid

    TEI 86, ces = 2, state = 8(established)

        spid2 configured, spid2 sent, spid2 valid

    Layer 3 Status:

    0 Active Layer 3 Call(s)

    Activated dsl 8 CCBs = 0

    The Free Channel Mask:  0x80000003

Total Allocated ISDN CCBs = 2

Router1#

说明得是关注流量触发了拨号接通以后所有得数据都可以传输，不仅仅是关注流量

13.2.  使用拨号接口

提问 捆绑多个物理接口为一个拨号接口

回答

捆绑两个ISDN BRI接口

Router1#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router1(config)#interface BRI0/0

Router1(config-if)#encapsulation ppp

Router1(config-if)#dialer pool-member 1

Router1(config-if)#isdn switch-type basic-ni

Router1(config-if)#isdn spid1 800555123400 5551234

Router1(config-if)#isdn spid2 800555123500 5551235

Router1(config-if)#ppp authentication chap

Router1(config-if)#exit

Router1(config)#interface BRI0/1

Router1(config-if)#encapsulation ppp

Router1(config-if)#dialer pool-member 1

Router1(config-if)#isdn switch-type basic-ni

Router1(config-if)#isdn spid1 800555123600 5551236

Router1(config-if)#isdn spid2 800555123700 5551237

Router1(config-if)#ppp authentication chap

Router1(config-if)#exit

Router1(config)#interface Dialer1

Router1(config-if)#ip address 10.1.99.55 255.255.255.0

Router1(config-if)#encapsulation ppp

Router1(config-if)#dialer remote-name dialhost

Router1(config-if)#dialer pool 1

Router1(config-if)#dialer idle-timeout 300

Router1(config-if)#dialer string 95551212

Router1(config-if)#dialer load-threshold 50 either

Router1(config-if)#dialer-group 1

Router1(config-if)#ppp authentication chap

Router1(config-if)#ppp multilink

Router1(config-if)#exit

Router1(config)#username dialhost password dialpassword

Router1(config)#ip route 0.0.0.0 0.0.0.0 10.1.99.1 180

Router1(config)#dialer-list 1 protocol ip list 101

Router1(config)#access-list 101 deny eigrp any any

Router1(config)#access-list 101 permit ip any any

Router1(config)#router eigrp 55

Router1(config-router)#network 10.0.0.0

Router1(config-router)#end

Router1#

主机端

dialhost#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

dialhost(config)#username Router1 password dialpassword

dialhost(config)#controller T1 0

dialhost(config-controller)#framing esf

dialhost(config-controller)#clock source line primary

dialhost(config-controller)#linecode b8zs

dialhost(config-controller)#pri-group timeslots 1-24

dialhost(config-controller)#exit

dialhost(config)#interface Serial0:23

dialhost(config-if)#encapsulation ppp

dialhost(config-if)#dialer rotary-group 1

dialhost(config-if)#dialer-group 1

dialhost(config-if)#isdn switch-type primary-dms100

dialhost(config-if)#isdn not-end-to-end 56

dialhost(config-if)#exit

dialhost(config)#interface Dialer1

dialhost(config-if)#ip address 10.1.99.1 255.255.255.0

dialhost(config-if)#encapsulation ppp

dialhost(config-if)#dialer in-band

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)#end

dialhost#

注释 本节实现得结果和13.1相同，配置也基本相同，不同得是这里没有使用dialer map命令，在物理接口上也没有配置IP地址，相关配置都在定义得逻辑拨号接口Dialer1上。在Server端使用了PRI

wade2007

13.3.  在AUX端口使用异步Modem

提问 在路由器得AUX端口连接异步Modem，用其作为拨号备份

回答

Router2#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router2(config)#interface Async65

Router2(config-if)#encapsulation ppp

Router2(config-if)#dialer in-band

Router2(config-if)#dialer pool-member 1

Router2(config-if)#ppp authentication chap

Router2(config-if)#async default routing

Router2(config-if)#exit

Router2(config)#interface Dialer1

Router2(config-if)#ip address 10.1.99.56 255.255.255.0

Router2(config-if)#encapsulation ppp

Router2(config-if)#dialer remote-name dialhost

Router2(config-if)#dialer pool 1

Router2(config-if)#dialer idle-timeout 300

Router2(config-if)#dialer string 95551212

Router2(config-if)#dialer-group 1

Router2(config-if)#ppp authentication chap

Router2(config-if)#exit

Router2(config)#line aux 0

Router2(config-line)#modem inout

Router2(config-line)#transport input all

Router2(config-line)#no exec

Router2(config-line)#speed 115200

Router2(config-line)#exit

Router2(config)#username dialhost password dialpassword

Router2(config)#ip route 0.0.0.0 0.0.0.0 10.1.99.1 180

Router2(config)#dialer-list 1 protocol ip list 101

Router2(config)#access-list 101 deny eigrp any any

Router2(config)#access-list 101 permit ip any any

Router2(config)#router eigrp 55

Router2(config-router)#network 10.0.0.0

Router2(config-router)#exit

Router2(config)#end

Router2#

注释 开始要先通过show line查找出AUX口得vty号码，也就是interface Async65 ，然后使用前面提到得拨号接口得方法进行配置，多了一个async default routing命令，因为缺省情况下异步口是禁止启用路由协议得。在对AUX端口配置时，首先一定要使用no exec来避免出现Modem不能响应得问题，同时建议调整速率，否则会缺省9.6 Kbps。

13.4.  使用备份接口

提问 在广域网物理接口断掉得情况下拨号

回答

Router1#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router1(config)#interface Serial0/0

Router1(config-if)#backup delay 0 300

Router1(config-if)#backup interface BRI0/0

Router1(config-if)#encapsulation frame-relay

Router1(config-if)#down-when-looped

Router1(config-if)#exit

Router1(config)#interface Serial0/0.1 point-to-point

Router1(config-subif)#ip address 10.1.1.10 255.255.255.252

Router1(config-subif)#frame-relay interface-dlci 50   

Router1(config-subif)#exit

Router1(config)#interface BRI0/0

Router1(config-if)#ip address 10.1.99.55 255.255.255.0

Router1(config-if)#encapsulation ppp

Router1(config-if)#dialer idle-timeout 300

Router1(config-if)#dialer map ip 10.1.99.1 name dialhost broadcast 95551212

Router1(config-if)#dialer load-threshold 50 either

Router1(config-if)#dialer-group 1

Router1(config-if)#isdn switch-type basic-ni

Router1(config-if)#isdn spid1 800555123400 5551234

Router1(config-if)#isdn spid2 800555123500 5551235

Router1(config-if)#ppp authentication chap

Router1(config-if)#ppp multilink

Router1(config-if)#exit

Router1(config)#dialer-list 1 protocol ip permit

Router1(config)#end

Router1#

注释 备份接口得配置要放在物理接口上而不是子接口上。一般不推荐使用此方法进行备份，因为很多广域网链路得问题不能体现在物理接口down掉上，并且在正常情况下会使备份接口处于禁用状态，这样会需要重新拨号，不能使用show isdn status等命令进行查看状态等问题。

13.5.  使用Dialer Watch

提问 使用思科得Dialer Watch特性来触发拨号备份

回答

Router1#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router1(config)#interface BRI0/0

Router1(config-if)#ip address 10.1.99.55 255.255.255.0

Router1(config-if)#encapsulation ppp

Router1(config-if)#dialer map ip 10.1.1.0 name dialhost broadcast 95551212

Router1(config-if)#dialer map ip 10.2.0.0 name dialhost broadcast 95551212

Router1(config-if)#dialer map ip 10.1.99.1 name dialhost broadcast 95551212

Router1(config-if)#dialer load-threshold 50 either

Router1(config-if)#dialer watch-group 1

Router1(config-if)#dialer-group 1

Router1(config-if)#isdn switch-type basic-ni

Router1(config-if)#isdn spid1 800555123400 5551234

Router1(config-if)#isdn spid2 800555123500 5551235

Router1(config-if)#ppp authentication chap

Router1(config-if)#ppp multilink

Router1(config-if)#exit

Router1(config)#router eigrp 55

Router1(config-router)#network 10.0.0.0

Router1(config-router)#exit

Router1(config)#username dialhost password cisco

Router1(config)#access-list 101 deny eigrp any any

Router1(config)#access-list 101 permit ip any any

Router1(config)#dialer-list 1 protocol ip list 101

Router1(config)#dialer watch-list 1 ip 10.2.0.0 255.255.0.0

Router1(config)#dialer watch-list 1 ip 10.1.1.0 255.255.255.0

Router1(config)#dialer watch-list 1 delay route-check initial 300

Router1(config)#dialer watch-list 1 delay disconnect 15

Router1(config)#end

Router1#

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