The Snort Team
Revision History
-Revision 3.1.22.0 2022-01-31 06:12:49 EST TST
+Revision 3.1.23.0 2022-02-09 05:15:12 EST TST
---------------------------------------------------------------------
* string snort.-R: <rules> include this rules file in the default
policy
* string snort.-r: <pcap>… (same as --pcap-list)
- * int snort.-s = 1518: <snap> (same as --snaplen); default is 1518
- { 68:65535 }
+ * int snort.-s: <snap> (same as --snaplen); default is 1518 {
+ 0:65535 }
* implied snort.-T: test and report on the current Snort
configuration
* string snort.-t: <dir> chroots process to <dir> after
Daemon mode
* string snort.--daq: <type> select packet acquisition module
(default is pcap)
- * int snort.--daq-batch-size = 64: <size> set the DAQ receive batch
- size { 1: }
+ * int snort.--daq-batch-size: <size> set the DAQ receive batch
+ size; default is 64 { 1: }
* string snort.--daq-dir: <dir> tell snort where to find desired
DAQ
* implied snort.--daq-list: list packet acquisition modules
to read - read mode is implied
* string snort.--pcap-dir: <dir> a directory to recurse to look for
pcaps - read mode is implied
- * string snort.--pcap-filter = .*cap: <filter> filter to apply when
- getting pcaps from file or directory
+ * string snort.--pcap-filter: <filter> filter to apply when getting
+ pcaps from file or directory
* int snort.--pcap-loop: <count> read all pcaps <count> times; 0
will read until Snort is terminated { 0:max32 }
* implied snort.--pcap-no-filter: reset to use no filter when
directory, including file, and config file respectively
* implied snort.--show-plugins: list module and plugin versions
* int snort.--skip: <n> skip 1st n packets { 0:max53 }
- * int snort.--snaplen = 1518: <snap> set snaplen of packet (same as
- -s) { 68:65535 }
+ * int snort.--snaplen: <snap> set snaplen of packet (same as -s) {
+ 0:65535 }
* implied snort.--stdin-rules: read rules from stdin until EOF or a
line starting with END is read
* implied snort.--talos: enable Talos tweak (same as --tweaks
* 119:276 (http_inspect) HTTP version in start line is 0
* 119:277 (http_inspect) HTTP version in start line is higher than
1
+ * 119:278 (http_inspect) HTTP gzip body with the FEXTRA flag set
Peg counts:
* -q quiet mode - suppress normal logging on stdout
* -R <rules> include this rules file in the default policy
* -r <pcap>… (same as --pcap-list)
- * -s <snap> (same as --snaplen); default is 1518 (68:65535)
+ * -s <snap> (same as --snaplen); default is 1518 (0:65535)
* -T test and report on the current Snort configuration
* -t <dir> chroots process to <dir> after initialization
* -U use UTC for timestamps
* --control-socket <file> to create unix socket
* --create-pidfile create PID file, even when not in Daemon mode
* --daq <type> select packet acquisition module (default is pcap)
- * --daq-batch-size <size> set the DAQ receive batch size (1:)
+ * --daq-batch-size <size> set the DAQ receive batch size; default
+ is 64 (1:)
* --daq-dir <dir> tell snort where to find desired DAQ
* --daq-list list packet acquisition modules available in optional
dir, default is static modules only
file, and config file respectively
* --show-plugins list module and plugin versions
* --skip <n> skip 1st n packets (0:max53)
- * --snaplen <snap> set snaplen of packet (same as -s) (68:65535)
+ * --snaplen <snap> set snaplen of packet (same as -s) (0:65535)
* --stdin-rules read rules from stdin until EOF or a line starting
with END is read
* --talos enable Talos tweak (same as --tweaks talos)
hex)
* implied snort.--create-pidfile: create PID file, even when not in
Daemon mode
- * int snort.--daq-batch-size = 64: <size> set the DAQ receive batch
- size { 1: }
+ * int snort.--daq-batch-size: <size> set the DAQ receive batch
+ size; default is 64 { 1: }
* string snort.--daq-dir: <dir> tell snort where to find desired
DAQ
* implied snort.--daq-list: list packet acquisition modules
pcaps - read mode is implied
* string snort.--pcap-file: <file> file that contains a list of
pcaps to read - read mode is implied
- * string snort.--pcap-filter = .*cap: <filter> filter to apply when
- getting pcaps from file or directory
+ * string snort.--pcap-filter: <filter> filter to apply when getting
+ pcaps from file or directory
* string snort.--pcap-list: <list> a space separated list of pcaps
to read - read mode is implied
* int snort.--pcap-loop: <count> read all pcaps <count> times; 0
stdout for text rule on stdin (specify delimiter or
[Snort_SO_Rule] will be used) { 16 }
* string snort.--run-prefix: <pfx> prepend this to each output file
- * int snort.-s = 1518: <snap> (same as --snaplen); default is 1518
- { 68:65535 }
* string snort.--script-path: <path> to a luajit script or
directory containing luajit scripts
* implied snort.--shell: enable the interactive command line
directory, including file, and config file respectively
* implied snort.--show-plugins: list module and plugin versions
* int snort.--skip: <n> skip 1st n packets { 0:max53 }
- * int snort.--snaplen = 1518: <snap> set snaplen of packet (same as
- -s) { 68:65535 }
+ * int snort.--snaplen: <snap> set snaplen of packet (same as -s) {
+ 0:65535 }
+ * int snort.-s: <snap> (same as --snaplen); default is 1518 {
+ 0:65535 }
* implied snort.--stdin-rules: read rules from stdin until EOF or a
line starting with END is read
* implied snort.--talos: enable Talos tweak (same as --tweaks
The TCP packet is invalid because it doesn’t have a SYN, ACK, or RST
flag set.
-116:424 (pbb) truncated ethernet header
+116:424 (eth) truncated ethernet header
The packet length is less than the minimum ethernet header size (14
bytes)
-116:424 (pbb) truncated ethernet header
+116:424 (eth) truncated ethernet header
A truncated ethernet header was detected.
is higher than 1. This alert does not apply to HTTP/2 or HTTP/3
traffic.
+119:278 (http_inspect) HTTP gzip body with the FEXTRA flag set
+
+The HTTP message body is gzip encoded and the FEXTRA flag is set in
+the gzip header.
+
121:1 (http2_inspect) invalid flag set on HTTP/2 frame
Invalid flag set on HTTP/2 frame header
The Snort Team
Revision History
-Revision 3.1.22.0 2022-01-31 06:12:35 EST TST
+Revision 3.1.23.0 2022-02-09 05:15:01 EST TST
---------------------------------------------------------------------
-A cmg says to output intrusion events in "cmg" format, which has
basic header details followed by the payload in hex and text.
-Note that you add to and/or override anything in your configuration
-file by using the --lua command line option. For example:
+Command line options have precedence over Lua configuration files.
+This can be used to make a custom run keeping all configuration files
+unchanged:
+
+--daq-batch-size=32
+
+will override daq.batch_size value.
+
+Notably, you can add to and/or override anything in your
+configuration file by using the --lua command line option. For
+example:
--lua 'ips = { enable_builtin_rules = true }'
* IPS rules may also have a wild card parameter, which is indicated
by a *. Used for unquoted, comma-separated lists such as service
and metadata.
- * The snort module has command line options starting with a -.
+ * The snort module has command line options starting with a -. The
+ options passed from command line override the options configured
+ via snort module.
* $ denotes variable names.
Some additional details to note:
Lua Configuration
+ * Some parameters could be configured via a command line option or
+ snort module. In this case a command line option has the highest
+ precedence, in turn, snort module configuration has precedence
+ over other modules.
* Configure the wizard and default bindings will be created based
on configured inspectors. No need to explicitly bind ports in
this case.
* process.set_uid
* snort.--bpf
* snort.-l
+ * trace.output
In addition, the following scenarios require a restart:
As with a number of features in Snort 3, the LibDAQ and DAQ module
configuration may be controlled using either the command line options
-or by configuring the daq Snort module in the Lua configuration.
+or by configuring the daq Snort module in the Lua configuration
+(command line option has higher precedence).
DAQ modules may be statically built into Snort, but the more common
case is to use DAQ modules that have been built as dynamically