there is no command to log inbound traffic. Probably, you can have a syslog server setup, whill would log all the activity through/on PIX to a syslog server. Later you can use these log files for your analysis.
You can download a syslog server from following link, if required.
The name of the tool is Kiwi Syslog Server.
http://www.kiwisyslog.com/php/download.php?syslogd_kiwitools
Install the server on any system connected to PIX, and then reboot the server.
Now enter following commands on your PIX :
pix(config)# logging host [interface_name] [ip_address]
pix(config)# logging trap [level]
pix(config)# logging on
[interface_name] ----> name of interface on which syslog server is connected
(inside).
[ip_address] ----> ip address of workstation where you install sylog server.
[level] ----> level of logging desired.
Different levels are as follows:
0 - Emergencies - System unusable messages.
1 - Alerts - Take immediate attention.
2 - Critical - Critical Condition.
3 - Errors - Error messages (this is the default level)
4 - Warnings - Warning messages.
5 - Notifications - Normal but significant condition.
6 - Informational - Informational message.
7 - Debugging - Debug messages and log FTP commands and WWW URLs.
Either level no. or level name can be used in the above command.
Here is a link which tells in detail about all the syslog messages on PIX-
http://www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_sw/v_63/63syslog/index.htm
Hope this is helpful.
Regards,
Vibhor.