MAC Address not updating - Printer Discovery

[akashfinning]

Hi Everyone, 

Need your help. We have been Discovering printers in our organisation but what we have found the MAC address is not getting updated with record even though I can see in entries at down there is a network adapter associated with each printer.

I have been discussed this with ServiceNow team and they advised there is a need of customisation in SNMP classify Probe.

Can you please help what customisation we required if anyone has done this in past?

Regards,

Akash

#ITOM #CMDB #Printers #MAC Address

[Amit Gujarathi · Accepted solution]

Hi @akashfinning ,
I trust you are doing great.

1. Navigate to the ServiceNow instance as an administrator.
2. Go to the "SNMP Classify Probes" module.
3. Locate the probe associated with printers, typically named something like "Printer Discovery Probe."
4. Open the probe for editing.

Within the SNMP classify probe customization, you'll need to add logic to extract and update the MAC address for each discovered printer. Here's a general outline of the steps involved:

1. Identify the SNMP OID (Object Identifier) used to retrieve the MAC address information from the printer device. You can refer to the printer's documentation or consult with your network team to obtain this OID.

2. Inside the SNMP classify probe, find the section where it processes and populates the discovered printer record.

3. Add code to extract the MAC address from the SNMP response and update the corresponding field in the printer record. Here's an example using JavaScript syntax:

// Extract the MAC address from the SNMP response
var macAddress = snmpResponse.get("<MAC_ADDRESS_OID>");

// Update the MAC address field in the printer record
current.u_mac_address = macAddress;

[akashfinning]

Thank you so much @Amit Gujarathi for a swift reply.

I would apply this and get back to you with the results.

Regards,

Akash

[akashfinning]

Hi @Amit Gujarathi , hope you doing good.

What I found is the MAC address OID is different for each manufacturer and model. So if this is the case then while updating probe script how we will cover all manufacturers with one script ?

Do I need to give different script for each OID as below for each manufacturer to make changes in Probe?

Your proposal:

1. Identify the SNMP OID (Object Identifier) used to retrieve the MAC address information from the printer device. You can refer to the printer's documentation or consult with your network team to obtain this OID.

// Extract the MAC address from the SNMP response
var macAddress = snmpResponse.get("<MAC_ADDRESS_OID>");

This is the reply I got from Lexmark

Please find enclosed the information I have received from Lexmark. Kindly inform me if any additional information is required.

Please note that the Mac address is called UAA on the Lexmark printers.

lexmac

OID: 1.3.6.1.4.1.641.1.7

Type: node

Description: This OID returns network‑address‑related data.

lexmacType

OID: 1.3.6.1.4.1.641.1.7.1

Type: DisplayString

Access type: readonly

Description: The type of network medium to which the network adapter is attached.

snmpwalk -c public -v 2c 157.184.142.246 1.3.6.1.4.1.641.1.7.4.0
SNMPv2-SMI::enterprises.641.1.7.4.0 = Hex-STRING: 00 21 B7 C3 CA BD

[akashfinning]

@Amit Gujarathi 
In our Discovery these are the phases Discovery is taking for each printers.

I think if amendment has to be done then it will be in SNMP -Identify and SNMP - Printing probe ?