1SHOREWALL-LOGGING(5) Configuration Files SHOREWALL-LOGGING(5)
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6 logging - Shorewall logging
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9 action:level
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11 NFLOG(nflog-parameters)
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13 ULOG(ulog-parameters)
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16 The disposition of packets entering a Shorewall firewall is determined
17 by one of a number of Shorewall facilities. Only some of these
18 facilities permit logging.
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20 1. The packet is part of an established connection. While the packet
21 can be logged using LOG rules in the ESTABLISHED section of
22 /etc/shorewall/rules[1], that is not recommended because of the
23 large amount of information that may be logged.
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25 2. The packet represents a connection request that is related to an
26 established connection (such as a data connection associated with
27 an FTP control connection[2]). These packets may be logged using
28 LOG rules in the RELATED section of shorewall-rules(5)[1].
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30 3. The packet is rejected because of an option in shorewall.conf[3](5)
31 or shorewall-interfaces(5)[4]. These packets can be logged by
32 setting the appropriate logging-related option in
33 /etc/shorewall/shorewall.conf[3].
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35 4. The packet matches a rule in shorewall-rules[1](5). By including a
36 syslog level (see below) in the ACTION column of a rule (e.g.,
37 “ACCEPT:info net $FW tcp 22”), the connection attempt will be
38 logged at that level.
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40 5. The packet doesn't match a rule so it is handled by a policy
41 defined in shorewall-policy(5)[5]. These may be logged by
42 specifying a syslog level in the LOG LEVEL column of the policy's
43 entry (e.g., “loc net ACCEPT info”).
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46 By default, Shorewall directs Netfilter to log using syslog (8). Syslog
47 classifies log messages by a facility and a priority (using the
48 notation facility.priority).
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50 The facilities defined by syslog are auth, authpriv, cron, daemon,
51 kern, lpr, mail, mark, news, syslog, user, uucp and local0 through
52 local7.
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54 Throughout the Shorewall documentation, the term level rather than
55 priority is used, since level is the term used by Netfilter. The syslog
56 documentation uses the term priority.
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59 Syslog levels are a method of describing to syslog (8) the importance
60 of a message. A number of Shorewall parameters have a syslog level as
61 their value.
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63 Valid levels are:
64 7 - debug (Debug-level
65 messages)
66 6 - info
67 (Informational)
68 5 - notice (Normal but
69 significant Condition)
70 4 - warning (Warning
71 Condition)
72 3 - err (Error
73 Condition)
74 2 - crit (Critical
75 Conditions)
76 1 - ale