System information

Troubleshooting ISDN Connections 17-387
ISDN: No Communication End-to-End
ISDN: No Communication End-to-End
Symptom: ISDN connection attempts are successful, but attempts to ping or otherwise
communicate end-to-end over an ISDN connection are unsuccessful.
PPP
5
encapsulation not configured
on interface
Step 1 Use the show running-config privileged exec command to view the
interface state. Check the output to see whether the encapsulation
ppp interface configuration command is present.
Step 2 If PPP encapsulation is not configured, configure the interface with
the encapsulation ppp command.
Step 3 Verify that PPP encapsulation is being used by checking the show
running-config output again.
No route to remote network Step 1 Enter the show route privileged exec command for the particular
protocol you are using. For example, if you are using IP, enter show
ip route ip-address. If the output says “Network not in table,” there
is no route to the remote network.
Step 2 If there are no routes to remote networks, you need to add static
routes using the appropriate command for the protocol you are
running. For example, to configure static IP routes, use the ip route
global configuration command.
Step 3 You also need to configure floating static routes so that there will be
routes to the remote networks if the primary link goes down.
For information on configuring floating static routes, refer to the Cisco IOS
Wide-Area Networking Configuration Guide and Wide-Area Networking
Command Reference.
Misconfigured dialer map command
Step 1 Use the show running-config privileged exec command to view the
router configuration. Look for dialer map interface configuration
command entries.
Step 2 Make sure that the dialer maps point to the correct next hop address.
Also ensure that the next hop address is in the same subnet as the
local DDR
6
interface address.
For detailed information on configuring dialer maps, refer to the Cisco IOS
Wide-Area Networking Configuration Guide and Wide-Area Networking
Command Reference.
Missing dialer-group command
Step 1 A dialer group must be configured on the local and remote router
interfaces. Use the show running-config privileged exec command
to view the remote router configuration. Look for a dialer-group
interface configuration command entry.
Step 2 If the remote router interface has no dialer-group command entry,
you must configure a dialer group
on the interface. Use the dialer-group group-number interface
configuration command. Make sure the group number corresponds
to the group number referenced in dialer list command entries.
For more information, refer to the Cisco IOS Wide-Area Networking
Configuration Guide and Wide-Area Networking Command Reference.
1 CHAP = Challenge Handshake Authentication Protocol
2 PAP = Password Authentication Protocol
3 TACACS = Terminal Access Controller Access Control System
4 AAA = authentication, authorization, and accounting
5 PPP = Point-to-Point Protocol
6 DDR = dial-on-demand routing
Possible Problem Solution