A Logo

Feel free to include my content in your page via my
RSS feed

Help Irongeek.com pay for
bandwidth and research equipment:

Search Irongeek.com:

Irongeek Button
Social-engineer-training Button

Help Irongeek.com pay for bandwidth and research equipment:


Man page of YERSINIA


Section: (8)
Updated: $Date: 2006/02/17 22:48:40 $
Index of this MAN page

Back To MAN Pages From BackTrack 5 R1 Master List  


Yersinia - A FrameWork for layer 2 attacks



yersinia [-hVGIDd] [-l logfile] [-c conffile] protocol [-M] [protocol_options]  


yersinia is a framework for performing layer 2 attacks. The following protocols have been implemented in Yersinia current version: Spanning Tree Protocol (STP), VLAN Trunking Protocol (VTP), Hot Standby Router Protocol (HSRP), Dynamic Trunking Protocol (DTP), IEEE 802.1Q, Cisco Discovery Protocol (CDP), Dynamic Host Configuration Protocol (DHCP) and, finally, the Inter-Switch Link Protocol (ISL).

Some of the attacks implemented will cause a DoS in a network, other will help to perform any other more advanced attack, or both. In addition, some of them will be first released to the public since there isn't any public implementation.

Yersinia will definitely help both pen-testers and network administrators in their daily tasks.

Some of the mentioned attacks are DoS attacks, so TAKE CARE about what you're doing because you can convert your network into an UNSTABLE one.

A lot of examples are given at this page EXAMPLES section, showing a real and useful program execution.  


-h, --help
Help screen.
-V, --Version
Program version.
Start a graphical GTK session.
-I, --interactive
Start an interactive ncurses session.
-D, --daemon
Start the network listener for remote admin (Cisco CLI emulation).
Enable debug messages.
-l logfile
Save the current session to the file logfile. If logfile exists, the data will be appended at the end.
-c conffile
Read/write configuration variables from/to conffile.
Disable MAC spoofing.


The following protocols are implemented in yersinia current version:

Spanning Tree Protocol (STP and RSTP)
Cisco Discovery Protocol (CDP)
Hot Standby Router Protocol (HSRP)
Dynamic Host Configuration Protocol (DHCP)
Dynamic Trunking Protocol (DTP)
IEEE 802.1Q
VLAN Trunking Protocol (VTP)
Inter-Switch Link Protocol (ISL)


Spanning Tree Protocol (STP): is a link management protocol that provides path redundancy while preventing undesirable loops in the network. The supported options are:

-version version
BPDU version (0 STP, 2 RSTP, 3 MSTP)
-type type
BPDU type (Configuration, TCN)
-flags flags
BPDU Flags
-id id
-cost pathcost
BPDU root path cost
-rootid id
-bridgeid id
BPDU Bridge ID
-portid id
-message secs
BPDU Message Age
-max-age secs
BPDU Max Age (default is 20)
-hello secs
BPDU Hello Time (default is 2)
-forward secs
BPDU Forward Delay
-source hw_addr
Source MAC address
-dest hw_addr
Destination MAC address
-interface iface
Set network interface to use
-attack attack
Attack to launch

Cisco Discovery Protocol (CDP): is a Cisco propietary Protocol which main aim is to let Cisco devices to communicate to each other about their device settings and protocol configurations. The supported options are:
-source hw_addr
MAC Source Address
-dest hw_addr
MAC Destination Address
-v version
CDP Version
-ttl ttl
Time To Live
-devid id
Device ID
-address address
Device Address
-port id
Device Port
-capability cap
Device Capabilities
-version version
Device IOS Version
-duplex 0|1
Device Duplex Configuration
-platform platform
Device Platform
-ipprefix ip
Device IP Prefix
-phello hello
Device Protocol Hello
-mtu mtu
Device MTU
-vtp_mgm_dom domain
Device VTP Management Domain
-native_vlan vlan
Device Native VLAN
-voip_vlan_r req
Device VoIP VLAN Reply
-voip_vlan_q query
Device VoIP VLAN Query
-t_bitmap bitmap
Device Trust Bitmap
-untrust_cos cos
Device Untrusted CoS
-system_name name
Device System Name
-system_oid oid
Device System ObjectID
-mgm_address address
Device Management Address
-location location
Device Location
-attack attack
Attack to launch

Hot Standby Router Protocol (HSRP):

Inter-Switch Link Protocol (ISL):

VLAN Trunking Protocol (VTP):

Dynamic Host Configuration Protocol (DHCP):

IEEE 802.1Q:

Dynamic Trunking Protocol (DTP):



Attacks Implemented in STP:
0: NONDOS attack sending conf BPDU
1: NONDOS attack sending tcn BPDU
2: DOS attack sending conf BPDUs
3: DOS attack sending tcn BPDUs
4: NONDOS attack Claiming Root Role
5: NONDOS attack Claiming Other Role
6: DOS attack Claiming Root Role with MiTM

Attacks Implemented in CDP:
0: NONDOS attack sending CDP packet
1: DOS attack flooding CDP table
2: NONDOS attack Setting up a virtual device

Attacks Implemented in HSRP:
0: NONDOS attack sending raw HSRP packet
1: NONDOS attack becoming ACTIVE router
2: NONDOS attack becoming ACTIVE router (MITM)

Attacks Implemented in DHCP:
0: NONDOS attack sending RAW packet
1: DOS attack sending DISCOVER packet
2: NONDOS attack creating DHCP rogue server
3: DOS attack sending RELEASE packet

Attacks Implemented in DTP:
0: NONDOS attack sending DTP packet
1: NONDOS attack enabling trunking

Attacks Implemented in 802.1Q:
0: NONDOS attack sending 802.1Q packet
1: NONDOS attack sending 802.1Q double enc. packet
2: DOS attack sending 802.1Q arp poisoning

Attacks Implemented in VTP:
0: NONDOS attack sending VTP packet
1: DOS attack deleting all VTP vlans
2: DOS attack deleting one vlan
3: NONDOS attack adding one vlan
4: DOS attack Catalyst zero day

Attacks Implemented in ISL:
None at the moment



The GTK GUI (-G) is a GTK graphical interface with all of the yersinia powerful features and a professional 'look and feel'.



The ncurses GUI (-I) is a ncurses (or curses) based console where the user can take advantage of yersinia powerful features.

Press 'h' to display the Help Screen and enjoy your session :)  


The Network Daemon (-D) is a telnet based server (ala Cisco mode) that listens by default in port 12000/tcp waiting for incoming telnet connections.

It supports a CLI similar to a Cisco device where the user (once authenticated) can display different settings and can launch attacks without having yersinia running in her own machine (specially useful for Windows users).  


- Send a Rapid Spanning-Tree BPDU with port role designated, port state agreement, learning and port id 0x3000 to eth1:

yersinia stp -attack 0 -version 2 -flags 5c -portid 3000 -interface eth1

- Start a Spanning-Tree nonDoS root claiming attack in the first nonloopback interface (keep in mind that this kind of attack will use the first BPDU on the network interface to fill in the BPDU fields properly):

yersinia stp -attack 4

- Start a Spanning-Tree DoS attack sending TCN BPDUs in the eth0 interface with MAC address 66:66:66:66:66:66:

yersinia stp -attack 3 -source 66:66:66:66:66:66



The README file contains more in-depth documentation about the attacks.



Yersinia is Copyright (c)






Alfredo Andres Omella <alfredo@yersinia.net>
David Barroso Berrueta <tomac@yersinia.net>




This document was created by man2html, using the manual pages.
Time: 07:34:21 GMT, September 13, 2011

Printable version of this article

15 most recent posts on Irongeek.com:

If you would like to republish one of the articles from this site on your webpage or print journal please contact IronGeek.

Copyright 2016, IronGeek
Louisville / Kentuckiana Information Security Enthusiast