Learning by Doing: CISCO Certified Network ... - SCN Research

Watch out! This one can really be tough to stop on your router. Remember your
up arrow to quickly find the “undebug all” to try stopping this. You may even
have to disconnect the line again to help slow down the debug messages even
after you have turned off all debugging. Then do it on the other end of the serial
line (router “leftist”):
leftist (config)#int s0/1
leftist (config-if)#enc ppp
leftist (config-if)#ppp authentication pap
leftist (config-if)#ppp pap sent-username prophet password legodoom
leftist (config-if)#exit
leftist(config)#username prophet password legodoom
As soon as you put in the ppp pap username/passwords you should see something
like this:
leftist(config)#int s0/1
leftist(config-if)#ppp pap sent-username prophet password legodoom
leftist(config-if)#01:23:27: %LINEPROTO-5-UPDOWN: Line protocol on
Interface Serial0/1, changed state to up
leftist(config-if)#01:23:29: %LINK-3-UPDOWN: Interface Serial0/1, changed
state to up
leftist(config-if)#
Notice the process here…the line protocol comes up then the state comes up.
6. Let’s look at our PAP negotiation process:
1. leftist#debug ppp negotiation
2. PPP protocol negotiation debugging is on
3. leftist#
4. 01:24:37:%LINK-3-UPDOWN: Interface Serial0/1, changed state to down
5. 01:24:37: Se0/1 IPCP: State is Closed
6. 01:24:37: Se0/1 CDPCP: State is Closed
7. 01:24:37: Se0/1 PPP: Phase is TERMINATING
8. 01:24:37: Se0/1 LCP: State is Closed
9. 01:24:37: Se0/1 PPP: Phase is DOWN
10. 01:24:37: Se0/1 IPCP: Remove route to 200.200.200.1
11. 01:24:38: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Serial0/1, changed state to down
12. 01:24:46: %LINK-3-UPDOWN: Interface Serial0/1, changed state to up
13. 01:24:46: Se0/1 PPP: Treating connection as a dedicated line
14. 01:24:46: Se0/1 PPP: Phase is ESTABLISHING, Active Open
15. 01:24:46: Se0/1 LCP: O CONFREQ [Closed] id 76 len 14
16. 01:24:46: Se0/1 LCP: AuthProto PAP (0x0304C023)
17. 01:24:46: Se0/1 LCP: MagicNumber 0x01E48949 (0x050601E48949)
18. 01:24:46: Se0/1 LCP: I CONFREQ [REQsent] id 187 len 14
19. 01:24:46: Se0/1 LCP: AuthProto PAP (0x0304C023)
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