USER’S GUIDE472 CyberSWITCHPPP P ACKET T RACE MESSAGESPPP Packet Trace allows you to display the PPP protocol negotiation that takes place when a linkis established. This information is useful when diagnosing mismatches in configuration betweentwo systems. PPP Packet Trace puts PPP packet information into the Report log, which can beaccessed by using thedr command. Enable this feature by using thetrace ppp on command,and disable it withtrace ppp off. Two other commands are also available,trace ppp npandtrace ppp cp.trace ppp np only enables the tracing of Network Protocol packetsreceived and sent by the system. When thetrace ppp np command is used, no Control Protocolpackets will be reported to the system message log.trace ppp cp only enables the tracing ofControl Protocol packets received and sent by the system. When thetrace ppp cp command isused, no Network Protocol packets will be reported to the system message log.The following is the format of a PPP trace line as it is displayed bydr:[connection Id] [packet direction] [protocol type] [packet type]where:[connection Id]Identifies the connection. The Id is a numerical value, allowing you to distinguishconnections. The numerical value represents the order in which the connections aregenerated.[packet direction]Indicates the packet direction. IN means received packet, OUT means transmitted packet.[protocol type]Indicates the type of protocol used for negotiation. When a connection is made betweentwo devices, there are three different phases. The last two phases deal with the protocoltype and the options negotiated.The following table summarizes the protocol types:[packet type]A code field that indicates the type of command that the packet contains. PPP ControlProtocol negotiation uses the following commands:Protocol Options NegotiatedLink ControlProtocolAuthentication Protocol (PAP,CHAP)Multilink Protocol (MRRU, EndpointDiscriminator)PAPCHAPPassword validationShared Secret validationCompression(CCP)Encryption(ECP)IPCPBCPIPXCPATCPCompression optionsEncryption optionsIP addressBridge optionsIPX optionsAppletalk options