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[snmp] Net::Netmask not present: no scans possible [closed]

Hello there,

currently i am setting up OCS NG inventory to use the inventorized Data in a CMDB. 

Client version: 2.3

Server (Software):

  • PHP-Version : 5.6.33
  • Webserver : Apache/2.4.18 (Ubuntu)
  • Datenbank-Server : (Ubuntu) version 5.7.21-0ubuntu0.16.04.1
  • Version OCSReports: 2.4.1

So far everything worked really smooth and without many complications. But now i am facing an issue with the SNMP Feature which i cannot find a solution for - as soon as i configure the Networks Scans parameter SNMP_NETWORK to any value (e.g.,

i can see the following debug on clientside after the hostinventorization is completed:

[debug] =END=SERVER RET======

[debug] Calling handlers : `end_handler'

[debug] [snmp] Calling snmp_end_handler

[debug] [snmp] Snmp: Scanning network

[debug] [snmp] Net::Netmask not present: no scan possible

[debug] [snmp] Net::Netmask not present: no scan possible

[debug] [snmp] Snmp: Ending Scanning network

and, of course, i dont receive any SNMP Data from the desired Network.

No matter how the Notation of the Network is done:




as soon as i leave the SNMP_NETWORK field empty, the default scan is taking part and the Hosts Network (e.g. is scanned from host 192.30.20.xx)

since i can not / dont want to provide an extra machine just for the SNMP scans in every Network, i am looking for a solution here.

The current configuration:

OCS Server:
-Computer configuration: Network scans

IPDISCOVER: Standard state



Client configuration:









Also i am wondering, that every SNMP device in the Network is being connected to (or at least trying to). Except the Gateway (Firewall)! 

SNMPwalk to the firewall/Gateway is delivering lots of information but the OCS agent just doesnt connect (or at least it is not even trying to connect) to the Gateway (x.x.x.1) Address...? This might be related...?

Anybody can lead me on the right path? :)

thanks and best regards,


closed with the note: Problem solved
in SNMP by (200 points)
closed by

2 Answers

+1 vote
Best answer

Net::Netmask perl module is mandatory for snmp. Routines of this module are used in several files of the agent.

We'll update the agent installer to care for this module.


by (88.5k points)
selected by
0 votes
perfect! i almost knew i was just missing something stupid... :D

thanks a lot for that, Frank!
by (200 points)
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