Writing a new driver for Netshot¶

Introduction¶

Netshot uses drivers to talk to the network equipment. These drivers are JavaScript files. Netshot is distributed with a number of drivers, but anyone may write and load new drivers.

Information to collect¶

Before writing any code, you need to get answers for all the following questions.

Note

For a better understanding, examples of answers are given for the Cisco IOS driver.

What is the name of the vendor?

Cisco

What is the name of the operating system?

IOS

Assuming SNMP is configured on the device, what is the result of the following command (executed on an allowed NMS)?

snmpwalk -v2c -c [community] [IP of the device] 1.3.6.1.2.1.1

iso.3.6.1.2.1.1.1.0 = STRING: "Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 15.0(2)SE9, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2015 by Cisco Systems, Inc.
Compiled Tue 01-Dec-15 07:02 by prod_rel_team"
iso.3.6.1.2.1.1.2.0 = OID: iso.3.6.1.4.1.9.1.516
iso.3.6.1.2.1.1.3.0 = Timeticks: (279047790) 32 days, 7:07:57.90
iso.3.6.1.2.1.1.4.0 = ""
iso.3.6.1.2.1.1.5.0 = STRING: "switch1.lab.sqdqsd.net"
iso.3.6.1.2.1.1.6.0 = STRING: "observium"
iso.3.6.1.2.1.1.7.0 = INTEGER: 6
iso.3.6.1.2.1.1.8.0 = Timeticks: (0) 0:00:00.00
iso.3.6.1.2.1.1.9.1.2.1 = OID: iso.3.6.1.4.1.9.7.129
iso.3.6.1.2.1.1.9.1.2.2 = OID: iso.3.6.1.4.1.9.7.115
...

If telnet is possible on this kind of device, enable it and capture the full sequence of login (copy/paste of the console).

toto@bla:~$ telnet 10.1.1.1
Trying 10.1.1.1...
Connected to 10.1.1.1.
Escape character is '^]'.

User Access Verification

Username: mqlskd
Password:
% Login invalid

Username: admin
Password:
switch1.lab#

Capture the full sequence of login via SSH (copy/paste the content of the console).

toto@bla:~$ ssh user1@10.1.1.1
Password:

switch1.lab#

What are the possible prompts (e.g. exec disable, exec enable, configuration mode) and how to switch from one to another?

switch1.lab#disable
switch1.lab>enable
Password:
switch1.lab#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
switch1.lab(config)#end
switch1.lab#

Type an unknown command and capture the output. (This is to recognize errors.)

switch1.lab#lkqjsd
Translating "lkqjsd"
% Unknown command or computer name, or unable to find computer address
switch1.lab#a
% Ambiguous command:  "a"

What is the important information to capture whenever running a snapshot, and what is the associated CLI command?

Each config:

Running-config (show running-config)

IOS image file (taken from show version)

IOS version (taken from show version)

Device level (no history):

Main memory size (taken from show version)

Config register (taken from show version)

Configuration saved (compare show running and show startup)

Provide a full example of each of these items.

Is there any paging system when displaying a long output? Capture it.

What is the key to press to go on?

Is there any command available to totally disable the paging without altering the configuration?

Yes, --More-- like this:
!
ip vrf VRF270
 rd 270:270
!
 --More--
Press space to go on.

Type terminal length 0 to avoid it.

Is there a way to recognize the name of the user who made the last configuration change to the device?

Yes, by looking at the first line in show run: ! Last configuration change at 18:13:06 UTC Tue Aug 21 2018 by user1

Is there any virtualization aspect on the device? (e.g. VDC)

No

How to find out the name of the device?

Look for ... Uptime in show version

How to find out the contact for the device?

Look for snmp-server contact in the running-config

How to find out the location of the device?

Look for snmp-server location in the running-config

How to find out the software version of the device?

Look at show version

How to find out the family of the device?

Look at show version

How to retrieve the hardware inventory of the device?

Use show inventory

How to find out the main serial number of the device?

Processor board ID in show version

How to find out the list of L2/L3 interfaces of the device? With the associated IP address, the associated MAC address, the VRF, the admin status.

Look at interface blocks in the configuration. Use show interface X to retrieve the MAC address.

switch1.lab#show interfaces GigabitEthernet 1/0/1
GigabitEthernet1/0/1 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 0021.a16d.9481 (bia 0021.a16d.9481)
...

Upon configuration change, will the device generate a specific Syslog message?

Yes, %SYS-5-CONFIG_I: Configured from console by user1.

Upon configuration change, will the device generate a specific SNMP trap?

Yes, OID 1.3.6.1.4.1.9.9.43.1.1.6.1.5 with value 3.

Writing the driver¶

Once you have gathered the answers above, you have everything needed to start writing the JavaScript driver itself. Use one of the drivers bundled with Netshot as a template, and adapt each section (connection, snapshot, compliance/inventory hooks) based on the answers you collected.