Troubleshoot PPP

If you experience PPP connection problems, you can use this checklist to gather error information. This checklist can help you identify error symptoms and resolve PPP connection problems.

Current and relevant information about program temporary fixes (PTFs) and troubleshooting is documented on the iSeries™ server TCP/IP home page Link outside Information Center . This link provides the latest information that supplements and overrides the information that is contained in this topic.

Required supporting material:
- Remote host type, operating system, and level
- iSeries server host operating system level
- All output files that are saved in an output queue with the same name as the profile
- Job logs for QTPPPCTL and QTPPPL2TP (if an L2TP profile)
- Connection script, if used in your environment
- Status of connection profile before and after the connection fails
Recommended supporting material:
- Line description
- Connection profile
  Option 6 from WRKTCPPTP prints the profile settings.
- Modem type and model
- Modem command strings
- Communications trace

The ITSO Redbook TCP/IP for iSeries server: More Cool Things Than Ever (SG24-5190) Link to PDF covers the following PPP problems. It also provides detailed problem resolution information.

Table 1. PPP problems from ITSO Redbook
Problem	Solution
Modem hardware configuration Wrong configuration of dip-switches and other hardware settings	Make sure that the modem is configured for the correct framing type. This can be either Asynchronous or Synchronous. Refer to the modem manual for more information.
Modem AT commands The modem you are trying to use is not in the predefined list of modems in iSeries Navigator.	Create a new modem.
PPP users and passwords You are getting user name and password errors when attempting a PPP connection.	Ensure that the user ID and password are entered using the same case. Ensure that the authentication protocol used by the peers is the same. Do not use PAP at one peer, while the other peer is configured as CHAP.
PPP lines for starting a connection profile Identified PPP lines are used by the same hardware resource.	Remember to vary off other lines using the same hardware resource.
PPP protocol Connection errors can occur due to misconfiguration of the PPP protocol.	Investigating the lower-levels of the PPP protocol may be necessary in some situations where the peers are unable to communicate with each other due to a configuration error. If the PPP log or the job log of the PPP job does not show any indication of the problem, you can investigate the problem by using the communications trace function.