Ethanalyzer
This chapter describes how to use Ethanalyzer as a Cisco NX-OS protocol analyzer tool.
This chapter includes the following section:
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Using Ethanalyzer
Using Ethanalyzer
Ethanalyzer is a Cisco NX-OS protocol analyzer tool based on the Wireshark (formerly Ethereal) open source code. Ethanalyzer is a command-line version of Wireshark that captures and decodes packets. You can use Ethanalyzer to troubleshoot your network and analyze the control-plane traffic.
To configure Ethanalyzer, use one or more of the following commands:
Table 26-1 Ethanalyzer Commands Used for Configuring
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switch# ethanalyzer local sniff-interface interface |
Captures packets sent or received by the supervisor and provides detailed protocol information. Note For all commands in this table, interface is control, ha-primary, ha-secondary, inband (packet interface) or mgmt (management interface). |
switch# ethanalyzer local sniff-interface interface detailed-dissection |
Displays detailed protocol information |
switch# ethanalyzer local sniff-interface interface limit-captured-frames |
Limits the number of frames to capture. |
switch# ethanalyzer local sniff-interface interface limit-frame-size |
Limits the length of the frame to capture. |
switch# ethanalyzer local sniff-interface interface capture-filter |
Filters the types of packets to capture. |
switch# ethanalyzer local sniff-interface interface display-filter |
Filters the types of captured packets to display. |
switch# ethanalyzer local sniff-interface interface dump-pkt |
Dump the packet in HEX/ASCII with possibly one line summary |
switch# ethanalyzer local sniff-interface interface write |
Saves the captured data to a file. |
switch# ethanalyzer local read file |
Opens a captured data file and analyzes it. |
Ethanalyzer does not capture data traffic that Cisco NX-OS forwards in the hardware. Ethanalyzer uses the same capture filter syntax as tcpdump. For more information, see the following URL:
http://www.tcpdump.org/tcpdump_man.html
For information about the syntax of the display filter, see the following URL:
http://wiki.wireshark.org/DisplayFilters
This example shows captured data (limited to four packets) on the management interface:
switch# ethanalyzer local sniff-interface mgmt limit-captured-frames 4
2012-10-01 19:15:23.794943 10.78.110.241 -> 72.163.145.51 SSH Encrypted response packet
len=64
2012-10-01 19:15:23.796142 10.78.110.241 -> 72.163.145.51 SSH Encrypted response packet
len=144
2012-10-01 19:15:23.796608 10.78.110.241 -> 72.163.145.51 SSH Encrypted response packet
len=144
2012-10-01 19:15:23.797060 10.78.110.241 -> 72.163.145.51 SSH Encrypted response packet
len=144
For more information about Wireshark, see the following URL: http://www.wireshark.org/docs/