The debug packet command is no longer supported in the PIX Firewall 7.x code.
In the new software code, the capture command is modified to include several new features and provides the same functionality that was provided by the debugpacket command. Issue the capture command to enable packet capture capabilities for packet sniffing and network fault isolation. Issue the no form of this command to disable packet capture capabilities.
For more information on the prerequisites for changing features and commands prior to a PIX upgrade to 7.x code, refer to these documents: