System information

Troubleshooting Dialin Connections

Book Title

16-364

Note For general problems associated with a modem that cannot send or receive data, refer to the

section “Dialin: Modem Cannot Send or Receive Data” earlier in this chapter.

Note For information on troubleshooting IP problems not speciﬁc to dialin connections, refer to

Chapter 7, “Troubleshooting TCP/IP.”

Table 16-10 outlines the problems that might cause this symptom and describes solutions to those

problems.

Table 16-10 Dialin: Modem Cannot Send or Receive IP Data

Possible Causes Suggested Actions

IP routing not conﬁgured on local or

remote router

Make sure that IP routing is enabled on the local and remote routers. For

detailed information about conﬁguring IP routing, refer to the Cisco IOS

Network Protocols Conﬁguration Guide, Part 1.

No default gateway speciﬁed on PC

Step 1 Use the show slip exec command and make sure that the speciﬁed IP

address is the same as the default gateway speciﬁcation on the PC.

Step 2 Check the speciﬁed default gateway address on the PC. If the IP

address is not correct, specify the correct address. For instructions on

verifying and changing the default gateway address on the

workstation, refer to the vendor documentation.

Hardware ﬂow control not

conﬁgured on local or remote

modem or router

Step 1 Use the show line aux-line-number exec command and look for the

following in the Capabilities ﬁeld (see Figure 16-2):

Capabilities: Hardware Flowcontrol In, Hardware

Flowcontrol Out

If there is no mention of hardware ﬂow control in this ﬁeld, hardware

ﬂow control is not enabled on the line. Hardware ﬂow control for

access server-to-modem connections is recommended.

For an explanation of the output of the show line command, see the

“Using debug Commands” section earlier in this chapter.