Specifications

5-6
Cisco AS5x00 Case Study for Basic IP Modem Services
11/24/1999
Section 5 Configuring PPP and Authentication
Testing Asynchronous PPP Connections
Step 4
Go to the NAS terminal screen to observe and interpret the debug output messages. As the call enters
the NAS, debug output is created.
When examining PPP between two remote peers:
a.
First check to see if DSR came up.
b.
Verify that both sides get through LCP negotiation. If they do, move on to check authentication.
c.
After authentication succeeds, check IPCP negotiation.
d.
If no debug output appears, troubleshoot ISDN Q.931. Use the
debug isdn q931
command.
Given the debug commands entered in Step 1, the following debug output should be generated by the
call:
*Sep 24 13:05:49.052: AAA: parse name=tty1/2/09 idb type=10 tty=441
*Sep 24 13:05:49.052: AAA: name=tty1/2/09 flags=0x1D type=4 shelf=0 slot=1 adapter=2
port=9 channel=0
*Sep 24 13:05:49.052: AAA: parse name=Serial1/0/0:4:21 idb type=12 tty=-1
*Sep 24 13:05:49.052: AAA: name=Serial1/0/0:4:21 flags=0x5D type=1 shelf=0 slot=
1 adapter=0 port=4 channel=21
In this example, the call enters the NAS on channel 1/0/0:4:21. This channel maps to the 21st DS0
channel of the 4th PRI line of a CT3 card. Eventually the call terminates on modem 441.
*Sep 24 13:05:49.052: AAA/MEMORY: create_user (0x63E8FB70) user='' ruser='' port
='tty1/2/09' rem_addr='4089548211/51121' authen_type=ASCII service=LOGIN priv=1
*Sep 24 13:05:49.052: AAA/AUTHEN/START (1586904428): port='tty1/2/09' list='' ac
tion=LOGIN service=LOGIN
*Sep 24 13:05:49.052: AAA/AUTHEN/START (1586904428): using "default" list
*Sep 24 13:05:49.052: AAA/AUTHEN/START (1586904428): Method=LOCAL*Sep 24
13:05:49.052: AAA/AUTHEN (1586904428): status = GETUSER
*Sep 24 13:05:49.072: AAA/AUTHEN/ABORT: (1586904428) because Autoselected.
*Sep 24 13:05:49.072: AAA/MEMORY: free_user (0x63E8FB70) user='' ruser='' port='
An authentication start packet is sent by AAA, and it searches the local username database as the default
authentication method.
tty1/2/09' rem_addr='4089548211/51121' authen_type=ASCII service=LOGIN priv=1
*Sep 24 13:05:51.076: As1/2/09 PPP: Treating connection as a dedicated line
*Sep 24 13:05:55.272: As1/2/09 PPP: Phase is AUTHENTICATING, by this end
*Sep 24 13:05:55.404: As1/2/09 PAP: I AUTH-REQ id 1 len 20 from "dude"
*Sep 24 13:05:55.404: As1/2/09 PAP: Authenticating peer dude
PPP is allowed to start on the interface. The client sends an authentication request called
dude
. PAP
authentication is used.
*Sep 24 13:05:55.404: AAA: parse name=Async1/2/09 idb type=10 tty=441
*Sep 24 13:05:55.404: AAA: name=Async1/2/09 flags=0x1D type=4 shelf=0 slot=1 ada
pter=2 port=9 channel=0
*Sep 24 13:05:55.404: AAA: parse name=Serial1/0/0:4:21 idb type=12 tty=-1
*Sep 24 13:05:55.404: AAA: name=Serial1/0/0:4:21 flags=0x5D type=1 shelf=0 slot=
1 adapter=0 port=4 channel=21
*Sep 24 13:05:55.404: AAA/MEMORY: create_user (0x63E8FB70) user='dude' ruser=''
port='Async1/2/09' rem_addr='4089548211/51121' authen_type=PAP service=PPP priv=1
*Sep 24 13:05:55.404: AAA/AUTHEN/START (693233173): port='Async1/2/09' list=''
action=LOGIN service=PPP
*Sep 24 13:05:55.404: AAA/AUTHEN/START (693233173): using "default" list
*Sep 24 13:05:55.404: AAA/AUTHEN (693233173): status = UNKNOWN
*Sep 24 13:05:55.404: AAA/AUTHEN/START (693233173): Method=LOCAL
*Sep 24 13:05:55.404: AAA/AUTHEN (693233173): status = PASS
*Sep 24 13:05:55.404: As1/2/09 PAP: O AUTH-ACK id 1 len 5
The example above shows that local authentication was successful.