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With dialer map statements, remember that the phone number you put in the dialer map is the phone number of the remote router, not the local one. Look at it this way - if you want to call a friend on your cell, you dont pick up your cell and dial your own number! Speaking of dialer map statements, dont forget the all-important broadcast option at the end of the command: R1(config-if)#dialer map ip 172.12.21.1 name R2 broadcast 5555555 The router will accept that command without the broadcast option, but routing protocol updates and hellos would not be able to travel across the line. (This command is also needed in frame relay map statements to allow broadcasts and multicasts to be transmitted.) PAP is PPPs clear-text authentication scheme, and clear text is a really bad idea. But if you do have to configure it, dont forget that PAP requires additional configuration -the ppp pap sent-username command. R1(config-if)#ppp pap sent-username R1 password CISCO Must set encapsulation to PPP before using PPP subcommands R1(config-if)# The error message we got while configuring the sent-username command is another important reminder - by default, a BRI line is running HDLC, not PPP. Since HDLC doesnt allow us to use either PAP or CHAP, well need to set the link to PPP with the encapsulation ppp command. R1(config-if)#encapsulation ppp R1(config-if)#ppp authentication pap R1(config-if)#ppp pap sent-username R1 password CISCO But before we configure any of this information, we should configure the ISDN switch-type. Why? Because without the switch-type configuration, it doesnt matter that we avoid the other four errors - the line will not come up. Configure the switch-type with the isdn switch-type command, and then verify it with show isdn status. R1(config)#isdn switch-type basic-ni R1#show isdn status Global ISDN Switchtype = basic-ni (output of this command cut here for clarity) If you forget this part of the configuration, the output of show isdn status wastes no time in reminding you! R1#show isdn status **** No Global ISDN Switchtype currently defined **** ISDN is an important part of your CCNA studies, and this knowledge still comes in handy in production networks as well. Keep studying, notice the details, run those debugs, and youll be a CCNA before you know it! |
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