This document contains a frequently asked question (FAQ) about the port
number display on an Adaptive Security Appliance (ASA).
Technical Tips Conventions for more information on document
When non-TCP/UDP connections are permitted or denied by an Access Control
List (ACL) on an ASA, why does the port number in the syslog generated by the
ASA show "(0)"?
A. The ASA only reports the port number for those L4 protocols (for
example, UDP and TCP) that have the concept of a source and destination port.
For all other protocols, the value of "0" is used as there is not a source or
destination port to report.
For example, here is the syslog generated when IP protocol 41 is
permitted by an ACL on the ASA:
%ASA-6-106100: access-list outside_in permitted 41 outside/10.2.3.2(0) ->
inside/192.168.1.2(0) hit-cnt 1 first hit [0xcbeb3083, 0xee26ad1a]
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