|| Dial in to the NAS from a client PC.
Ensure that the client PC is able to connect to the NAS by establishing a dial-in connection. As the call comes into the NAS, a LINK-3-UPDOWN message automatically appears on the NAS terminal screen. In the following example, the call comes into the NAS on asynchronous interface 14:
*Jan 1 21:22:18.410: %LINK-3-UPDOWN: Interface Async14, changed state to up
If this message is not displayed by the NAS, there is a problem with the dial-in configuration.
debug commands are turned on to display this log message. This message should be displayed within 30 seconds after the client first sends the call.
Enter this command to enable privileged EXEC mode. Enter your password if prompted:
Enter this command on the tunnel server to verify that the client received an IP address. The following example shows that user3 is using IP address 10.0.0.1.
Router# show caller user email@example.com
User: firstname.lastname@example.org, line Vi2.502, service PPPoVPDN
Connected for 1d10h
Timeouts: Limit Remaining Timer Type
- - -
PPP: LCP Open, CHAP (<-), IPCP
IP: Local 10.0.0.1, remote 172.16.2.247
Counts: 2052 packets input, 32826 bytes
2053 packets output, 106742 bytes
If an incorrect IP address or no IP address is displayed, there is a problem with IP addresses assignment. Verify the configuration of the
address command in the virtual template on the tunnel server.
Enter this command to verify that the interface is up, that LCP is open, and that no errors are reported. The following output shows a functional interface:
Router# show interfaces virtual-access 2.502
Virtual-Access2.502 is up, line protocol is up
Hardware is Virtual Access interface
Interface is unnumbered. Using address of Loopback1001 (18.104.22.168)
MTU 1454 bytes, BW 2000000 Kbit, DLY 100000 usec,
reliability 255/255, txload 1/255, rxload 5/255
Encapsulation PPP, LCP Open
PPPoVPDN vaccess, cloned from Virtual-Template1
Vaccess status 0x0
Protocol l2tp, tunnel id 30485, session id 55909
Keepalive set (60 sec)
2056 packets input, 32890 bytes
2057 packets output, 106950 bytes
Last clearing of ''show interface'' counters never
The virtual access interface is up and the line protocol is up, showing that virtual interface establishment was successful.
Enter this command on the tunnel server to verify that there are active VPDN sessions. This example shows output from a tunnel server with several active tunnels.
Router# show vpdn session
L2TP Session Information Total tunnels 4000 sessions 15960
LocID RemID TunID Username, Intf/ State Last Chg Uniq ID
43202 40336 22 user@ci..., Vi2.9171 est 1d10h 9184
34090 31996 22 user@ci..., Vi2.1734 est 1d10h 1735
1217 42591 22 user@ci..., Vi2.9312 est 1d10h 9325
6737 22325 22 user@ci..., Vi2.1729 est 1d10h 1730
59420 17035 34 user@ci..., Vi2.9338 est 1d10h 9351
45069 60982 34 user@ci..., Vi2.1645 est 1d10h 1646
27825 44751 34 user@ci..., Vi2.1653 est 1d10h 1654
24600 7627 34 user@ci..., Vi2.9096 est 1d10h 9109
13018 65037 43 user@ci..., Vi2.8166 est 1d10h 8179
43090 34448 43 user@ci..., Vi2.8176 est 1d10h 8189
31798 41505 43 user@c..., Vi2.15752 est 1d10h 15765
56832 64322 43 user@c..., Vi2.15655 est 1d10h 15668
53944 25409 48 user@c..., Vi2.14115 est 1d10h 14128
16215 52915 48 user@c..., Vi2.14134 est 1d10h 14147
17332 14000 48 user@ci..., Vi2.6630 est 1d10h 6643
12466 54817 48 user@ci..., Vi2.6622 est 1d10h 6635
28290 37822 50 user@ci..., Vi2.5094 est 1d10h 15905
44839 30137 50 user@c..., Vi2.15875 est 1d10h 15888
If there is no session established for the client, perform the troubleshooting steps in the
Verifying and Troubleshooting Tunnel Establishment Between the NAS and the Tunnel Server.