Datasheet
Lab – Troubleshooting Basic PPP with Authentication
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*Jun 18 12:14:01.851: Se0/0/1 CHAP: I CHALLENGE id 1 len 23 from "R3"
*Jun 18 12:14:01.851: Se0/0/1 PPP: Sent CHAP SENDAUTH Request
*Jun 18 12:14:01.851: Se0/0/1 PPP: Sending AAA radius abort
R1(config-if)#
*Jun 18 12:14:04.860: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1,
changed state to up
*Jun 18 12:14:04.868: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/1,
changed state to down
*Jun 18 12:14:06.856: Se0/0/1 PPP: Using default call direction
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The debug output shows an unsuccessful CHAP negotiation process and the interface is going up and
down. More configuration errors exist for the link connecting R1 S0/0/1 and R3 S0/0/0.
e. Use the no debug ppp authentication or undebug all command to turn off the debug PPP output.
f. Use the show running-config | include username command to verify the correct username and
password configurations.
R1# show running-config | include username
username R2 password 0 chap123
username R3 password 0 chap123
Resolve all problems found. Record the commands used to correct the configuration.
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No problems exist.
Step 2: Examine the R2 configuration.
a. Use the show interfaces command to determine if PPP has been established on both serial links.
R2# show interfaces s0/0/0
Serial0/0/0 is up, line protocol is up
Hardware is GT96K Serial
Internet address is 192.168.12.2/30
MTU 1500 bytes, BW 1544 Kbit/sec, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Open
Open: IPCP, CDPCP, loopback not set
Keepalive set (10 sec)
CRC checking enabled
Last input 00:00:06, output 00:00:01, output hang never
Last clearing of "show interface" counters 00:18:22
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1158 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
53 packets input, 3055 bytes, 0 no buffer