TCP Dump

This is a tool to sniff the packet, when you want to examine that the expected packet really reached a node. You can run the tcpdump utility to sniff the packet headers on the network and save them on a dump file.

To use tcpdump:

  1. Select Maintenance > Troubleshooting > TCP Dump to display the configuration page.
  2. Complete the configuration as described below.
  3. Click Start Sniffing to start the tcpdump process.
  4. Initiate the action you want to debug, such as a user sign in.
  5. Click Stop Sniffing to write the tcpdump output to the screen.
  6. Click Get to save the output to a file, or click Delete to clear the output.

Settings

Guidelines

TCP Dump Status

Displays whether the utility is stopped or running.

Interface

Select the ports on which to sniff.

VLAN Port

Select the VLAN port.

Promiscuous mode

Select a promiscuous mode option.

Filter

Specify a filter expression. For information about TCP dump filter expressions, see the UNIX man page.

 

Example

Result

tcp port 80

Sniffs packets on TCP port 80.

port 80

Sniffs packets on TCP or UDP port 80.

ip

Sniffs the IP protocol.

tcp

Sniffs the TCP protocol.

dst #.#.#.#

Sniffs the destination IP address specified, where #.#.#.# is a valid IP address.

src #.#.#.#

Sniffs the source IP address specified, where #.#.#.# is a valid IP address.

port 80 or port 443

Sniffs on port 80 or port 443.

src #.#.#.# and dst #.#.#.#

Sniffs the source and destination IP addresses or hosts specified, where each #.#.#.# represents a valid IP address.

tcp port 80 or port 443 and dst #.#.#.# and src #.#.#.#

This example shows how to specify multiple parameters to create a filter that sniffs on TCP port 80, or on TCP or UDP port 443, and on the destination and source ports, where each #.#.#.# represents a valid IP address.