CISCODUMP(1) CISCODUMP(1)

NAME

ciscodump - Provide interfaces to capture from a remote Cisco router
through SSH.

SYNOPSIS

ciscodump [ --help ] [ --version ] [ --extcap-interfaces ]
[ --extcap-dlts ] [ --extcap-interface=<interface> ]
[ --extcap-config ] [ --extcap-capture-filter=<capture filter> ]
[ --capture ] [ --fifo=<path to file or pipe> ]
[ --remote-host=<IP address> ] [ --remote-port=<TCP port> ]
[ --remote-username=<username> ] [ --remote-password=<password> ]
[ --remote-filter=<filter> ] [ --sshkey=<public key path> ]
[ --remote-interface=<interface> ]

ciscodump --extcap-interfaces

ciscodump --extcap-interface=<interface> --extcap-dlts

ciscodump --extcap-interface=<interface> --extcap-config

ciscodump --extcap-interface=<interface>
--fifo=<path to file or pipe> --capture --remote-host=remoterouter
--remote-port=22 --remote-username=user
--remote-interface=<the router interface>

DESCRIPTION

Ciscodump is an extcap tool that relies on Cisco EPC to allow a user
to run a remote capture on a Cisco router in a SSH connection. The
minimum IOS version supporting this feature is 12.4(20)T. More
details can be found here:
<https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-embedded-packet-capture/datasheet_c78-502727.html>

Supported interfaces:

1. cisco

OPTIONS

--help

Print program arguments.

--version

Print program version.

--extcap-interfaces

List available interfaces.

--extcap-interface=<interface>

Use specified interfaces.

--extcap-dlts

List DLTs of specified interface.

--extcap-config

List configuration options of specified interface.

--capture

Start capturing from specified interface and save it in place
specified by --fifo.

--fifo=<path to file or pipe>

Save captured packet to file or send it through pipe.

--remote-host=<remote host>

The address of the remote host for capture.

--remote-port=<remote port>

The SSH port of the remote host.

--remote-username=<username>

The username for ssh authentication.

--remote-password=<password>

The password to use (if not ssh-agent and pubkey are used).
WARNING: the passwords are stored in plaintext and visible to all
users on this system. It is recommended to use keyfiles with a
SSH agent.

--remote-filter=<filter>

The remote filter on the router. This is a capture filter that
follows the Cisco IOS standards (
<https://www.cisco.com/c/en/us/support/docs/ip/access-lists/26448-ACLsamples.html>).
Multiple filters can be specified using a comma between them.
BEWARE: when using a filter, the default behavior is to drop all
the packets except the ones that fall into the filter.

Examples:

permit ip host MYHOST any, permit ip any host MYHOST (capture the traffic for MYHOST)

deny ip host MYHOST any, deny ip any host MYHOST, permit ip any any (capture all the traffic except MYHOST)

--sshkey=<SSH private key path>

The path to a private key for authentication.

--remote-interface=<remote interface>

The remote network interface to capture from.

--extcap-capture-filter=<capture filter>

Unused (compatibility only).

EXAMPLES

To see program arguments:

ciscodump --help

To see program version:

ciscodump --version

To see interfaces:

ciscodump --extcap-interfaces

Only one interface (cisco) is supported.

Example output

interface {value=cisco}{display=SSH remote capture}

To see interface DLTs:

ciscodump --extcap-interface=cisco --extcap-dlts

Example output

dlt {number=147}{name=cisco}{display=Remote capture dependent DLT}

To see interface configuration options:

ciscodump --extcap-interface=cisco --extcap-config

Example output

ciscodump --extcap-interface=cisco --extcap-config
arg {number=0}{call=--remote-host}{display=Remote SSH server address}
{type=string}{tooltip=The remote SSH host. It can be both an IP address or a hostname}
{required=true}
arg {number=1}{call=--remote-port}{display=Remote SSH server port}{type=unsigned}
{default=22}{tooltip=The remote SSH host port (1-65535)}{range=1,65535}
arg {number=2}{call=--remote-username}{display=Remote SSH server username}{type=string}
{default=<current user>}{tooltip=The remote SSH username. If not provided, the current
user will be used}
arg {number=3}{call=--remote-password}{display=Remote SSH server password}{type=string}
{tooltip=The SSH password, used when other methods (SSH agent or key files) are unavailable.}
arg {number=4}{call=--sshkey}{display=Path to SSH private key}{type=fileselect}
{tooltip=The path on the local filesystem of the private ssh key}
arg {number=5}{call--sshkey-passphrase}{display=SSH key passphrase}
{type=string}{tooltip=Passphrase to unlock the SSH private key}
arg {number=6}{call=--remote-interface}{display=Remote interface}{type=string}
{required=true}{tooltip=The remote network interface used for capture}
arg {number=7}{call=--remote-filter}{display=Remote capture filter}{type=string}
{default=(null)}{tooltip=The remote capture filter}
arg {number=8}{call=--remote-count}{display=Packets to capture}{type=unsigned}{required=true}
{tooltip=The number of remote packets to capture.}

To capture:

ciscodump --extcap-interface cisco --fifo=/tmp/cisco.pcap --capture --remote-host 192.168.1.10
--remote-username user --remote-interface gigabit0/0
--remote-filter "permit ip host 192.168.1.1 any, permit ip any host 192.168.1.1"

Note

Packet count is mandatory, hence the capture will start after
this number.

KNOWN ISSUES

The configuration of the capture on the routers is a multi-step
process. If the SSH connection is interrupted during it, the
configuration can be in an inconsistent state. That can happen also
if the capture is stopped and ciscodump can't clean the configuration
up. In this case it is necessary to log into the router and manually
clean the configuration, removing both the capture point
(WIRESHARK_CAPTURE_POINT), the capture buffer
(WIRESHARK_CAPTURE_BUFFER) and the capture filter
(WIRESHARK_CAPTURE_FILTER).

Another known issues is related to the number of captured packets
(--remote-count). Due to the nature of the capture buffer, ciscodump
waits for the capture to complete and then issues the command to show
it. It means that if the user specifies a number of packets above the
currently captured, the show command is never shown. Not only is the
count of the maximum number of captured packets, but it is also the
exact number of expected packets.

SEE ALSO

wireshark(1), tshark(1), dumpcap(1), extcap(4), sshdump(1)

NOTES

ciscodump is part of the Wireshark distribution. The latest version
of Wireshark can be found at <https://www.wireshark.org>.

HTML versions of the Wireshark project man pages are available at
<https://www.wireshark.org/docs/man-pages>.

AUTHORS

Original Author
Dario Lombardo <lomato[AT]gmail.com>

2024-03-27 CISCODUMP(1)