[root@ok Desktop]# yum search tcpdump
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
* base: mirrors.yun-idc.com
* extras: mirrors.yun-idc.com
* updates: mirrors.yun-idc.com
======================================================================= N/S Matched: tcpdump ========================================================================
tcpdump.x86_ : A network traffic monitoring tool
Name and summary matches only, use "search all" for everything.
[root@ok Desktop]# which tcpdump
/usr/sbin/tcpdump
[root@ok Desktop]# tcpdump -h
tcpdump version 4.1-PRE-CVS_2015_07_23
libpcap version 1.4.0
Usage: tcpdump [-aAdDefhIJKlLnNOpqRStuUvxX] [ -B size ] [ -c count ]
[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]
[ -i interface ] [ -j tstamptype ] [ -M secret ]
[ -P in|out|inout ]
[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]
[ -W filecount ] [ -y datalinktype ] [ -z command ]
[ -Z user ] [ expression ]
[root@ok Desktop]# yum search wireshark Loaded plugins: fastestmirror, refresh-packagekit, security Loading mirror speeds from cached hostfile * base: mirrors.yun-idc.com * extras: mirrors.yun-idc.com * updates: mirrors.yun-idc.com ================================================ N/S Matched: wireshark ================================================ wireshark-devel.i686 : Development headers and libraries for wireshark wireshark-devel.x86_ : Development headers and libraries for wireshark wireshark-gnome.x86_ : Gnome desktop integration for wireshark and wireshark-usermode wireshark.i686 : Network traffic analyzer wireshark.x86_ : Network traffic analyzer Name and summary matches only, use "search all" for everything.
安装：
[root@ok Desktop]# which wireshark /usr/sbin/wireshark
[root@ok Desktop]# rpm -qa|grep wireshark
wireshark-devel-1.8.10-17.el6.x86_
wireshark-1.8.10-17.el6.x86_
wireshark-gnome-1.8.10-17.el6.x86_
保存tcpdump抓包结果
[root@bass Desktop]# tcpdump -i eth0 -w dump.pcap -i #是指定要抓取的网卡 -w #指定结果保存的位置 [root@bass Desktop]# tcpdump -i eth0 -w dump.pcap -v tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes ^C1 packets captured 1 packets received by filter 0 packets dropped by kernel －v＃主要是为了得到Got 15这个数，当想要停止的时候，按下ctrl + c [root@bass Desktop]# ll -h dump.pcap -rw-r--r--. 1 tcpdump tcpdump 18K Aug 30 13:19 dump.pcap
在wireshark中打开：
[root@bass Desktop]# wireshark dump.pcap ＃linux下查看
我们用tcpdump抓包的时候，默认是显示这样的：
上图中标出三快区域，红色框内，是用来显示简单的数据包信息，我们用tcpdump抓包如时候，默认情况是显示成这样的；深蓝框内，是用来显示选中的数据包的详细信息，是按照TCP/IP四层结构显示的，第一行是数据链路层的信息，第二行是网络层信息（IP协议），第三行是传输层信息（TCP协议），第四层是应用层信息（HTTP协议），可以展开第一行用来观察具体的内容；最后一个区域淡蓝色框中，是用来显示此数据包的真实面目。（下图列清楚）
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sh-4.1# tcpdump -i eth0 -c 20 -w 20gebao -v tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 20 packets captured 20 packets received by filter 0 packets dropped by kernel
使用-c参数指定要监听到的数据包数量