gong - Device connector


go Go connects to network devices and automatically logs you in using cached TACACS credentials. It supports telnet, SSHv1/v2.

PLEASE NOTE: go is still named gong (aka “Go NG”) within the Trigger packaging due to legacy issues with naming conflicts. This will be changing in the near future.


Here is the usage output:

% gong
Usage: gong [options] [device]

Automatically log into network devices using cached TACACS credentials.

  -h, --help  show this help message and exit
  -o, --oob   Connect to device out of band first.


Caching credentials

If you haven’t cached your credentials, you’ll be prompted to:

% gong test2-abc
Connecting to test2-abc.net.aol.com.  Use ^X to exit.
/home/jathan/.tacacsrc not found, generating a new one!

Updating credentials for device/realm 'tacacsrc'
Username: jathan
Password (again):

Fetching credentials from /home/jathan/.tacacsrc

This functionality is provided by Tacacsrc.

Connecting to devices

Using gong is pretty straightforward if you’ve already cached your credentials:

% gong test1-abc
Connecting to test1-abc.net.aol.com.  Use ^X to exit.

Fetching credentials from /home/jathan/.tacacsrc
--- JUNOS 10.0S8.2 built 2010-09-07 19:55:32 UTC

Full or partial hostname matches are also acceptable:

% gong test2-abc.net.aol.com
Connecting to test2-abc.net.aol.com.  Use ^X to exit.

If there are multiple matches, you get to choose:

% gong test1
3 possible matches found for 'test1':
 [ 1] test1-abc.net.aol.com
 [ 2] test1-def.net.aol.com
 [ 3] test1-xyz.net.aol.com
 [ 0] Exit

Enter a device number: 3
Connecting to test1-xyz.net.aol.com.  Use ^X to exit.

If a partial name only has a single match, it will connect automatically:

% gong test1-a
Matched 'test1-abc.net.aol.com'.
Connecting to test1-abc.net.aol.com.  Use ^X to exit.

Out-of-band support

If a device has out-of-band (OOB) terminal server and ports specified within NetDevices, you may telnet to the console by using the -o flag:

% gong -o test2-abc
OOB Information for test2-abc.net.aol.com
telnet ts-abc.oob.aol.com 1234
Connecting you now...
Trying 10.302.134.584...
Connected to test2-abc.net.aol.com
Escape character is '^]'.

User Access Verification


Executing commands upon login

You may create a .gorc file in your home directory, in which you may specify commands to be executed upon login to a device. The commands are specified by the vendor name. Here is an example:

; .gorc - Example file to show how .gorc would work

; Specify the commands you would like run upon login for each vendor name. The
; vendor name must match the one found in the CMDB for the manufacturer of the
; hardware. Currently these are:
;     A10: a10
;  Arista: arista
; Brocade: brocade
;   Cisco: cisco
;  Citrix: citrix
;    Dell: dell
; Foundry: foundry
; Juniper: juniper
; Format:
; vendor:
;     command1
;     command2
    request system reboot
    set cli timestamp
    monitor start messages
    show system users

    term mon


    show clock

    show clock

(You may also find this file at configs/gorc.example within the Trigger source tree.)

Notice for Juniper one of the commands specified is request system reboot. This is bad! But don’t worry, only a very limited subset of root commands are allowed to be specified within the .gorc, and these are:


Any root commands not permitted will be filtered out prior to passing them along to the device.

Here is an example of what happens when you connect to a Juniper device with the specified commands in the sample .gorc file displayed above:

% gong test1-abc
Connecting to test1-abc.net.aol.com.  Use ^X to exit.

Fetching credentials from /home/jathan/.tacacsrc
--- JUNOS 10.0S8.2 built 2010-09-07 19:55:32 UTC
jathan@test1-abc> set cli timestamp
Mar 28 23:05:38
CLI timestamp set to: %b %d %T

jathan@test1-abc> monitor start messages

jathan@test1-abc> show system users
Jun 28 23:05:39
11:05PM  up 365 days, 13:44, 1 user, load averages: 0.09, 0.06, 0.02
USER     TTY      FROM                              LOGIN@  IDLE WHAT
jathan   p0       awesome.win.aol.com              11:05PM     - -cli (cli)



Authentication failures

If gong fails to connect, it tries to tell you why, and in the event of an authentication failure it will give you the opportunity to update your stored credentials:

Fetching credentials from /home/j/jathan/.tacacsrc

Connection failed for the following reason:

'\n\n% Authentication failed.\n\n\nUser Access Verification\n\nUsername:'

Authentication failed, would you like to update your password? (Y/n)

Blank passwords

When initially caching credentials, your password cannot be blank. If you try, gong complains:

Updating credentials for device/realm 'tacacsrc'
Username: jathan
Password (again):

Password cannot be blank, try again!

If gong detects a blank password in an existing .tacacsrc file, it will force you to update it:

Missing password for 'aol', initializing...

Updating credentials for device/realm 'aol'
Username [jathan]: