Shell; Tcpdump - Fujitsu ETERNUS DSP Series Cli Reference Manual

2. CLI Commands

shell

shell
■
COMMAND NAME
shell
■ SYNOPSIS
shell
■
DESCRIPTION
Run a command using shell. The shell function concatenate its arguments, separating each by a space, and
passes this string to the shell ($SHELL if set, otherwise /usr/bin/sh).

tcpdump

■ COMMAND NAME
tcpdump
■ SYNOPSIS
tcpdump [ -AbdDefIKlLnNOpqRStuUvxX ] [ -B buffer_size ] [ -c count ]
[ -C file_size ] [ -G rotate_seconds ] [ -F file ]
[ -i interface ] [ -m module ] [ -M secret ]
[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]
[ -W filecount ]
[ -E spi@ipaddr algo:secret,... ]
[ -y datalinktype ] [ -z postrotate-command ] [ -Z user ]
[ expression ]
■ DESCRIPTION
Dump traffic on a network. Tcpdump prints out a description of the contents of packets on a network interface
that match the boolean expression. It can also be run with the -w flag, which causes it to save the packet data to
a file for later analysis, and/or with the -r flag, which causes it to read from a saved packet file rather than to read
packets from a network interface (please note tcpdump is protected via an enforcing apparmor(7) profile in
Ubuntu which limits the files tcpdump may access). In all cases, only packets that match expression will be pro-
cessed by tcpdump. Tcpdump will, if not run with the -c flag, continue capturing packets until it is inter- rupted by
a SIGINT signal (generated, for example, by typing your interrupt character, typically control-C) or a SIGTERM sig-
nal (typically generated with the kill(1) command); if run with the -c flag, it will capture packets until it is inter-
rupted by a SIGINT or SIGTERM signal or the specified number of packets have been processed. When tcpdump
finishes capturing packets, it will report counts of: packets ``captured'' (this is the number of packets that tcp-
dump has received and processed); packets ``received by filter'' (the meaning of this depends on the OS on
which you're running tcpdump, and possibly on the way the OS was configured - if a filter was specified on the
command line, on some OSes it counts packets regardless of whether they were matched by the filter expression
and, even if they were matched by the filter expression, regardless of whether tcpdump has read and processed
them yet, on other OSes it counts only packets that were matched by the filter expres- sion regardless of whether
tcpdump has read and processed them yet, and on other OSes it counts only packets that were matched by the fil-
ter expression and were processed by tcpdump); packets ``dropped by kernel'' (this is the number of packets that
23 ETERNUS DSP CLI Reference Guide