SNMP
SNMP Drivers
Various SNMP devices might require special measures to get information, e.g. some devices provide additional information for interfaces only under vendor OIDs, etc. To address this, NetXMS provides a concept of SNMP drivers. SNMP driver is detected automatically.
If SNMP driver was not automatically detected, it’s possible to set it manually by specifying driver name in custom attribute snmp.driver
on a node.
- Possible SNMP driver names are:
AT
BAYSTACK
CAMBIUM-CNPILOT
CAMBIUM-EPMP
CATALYST-2900XL
CATALYST-GENERIC
CISCO-ESW
CISCO-GENERIC
CISCO-NEXUS
CISCO-SB
CISCO-WLC
DELL-PWC
DLINK
ERS8000
EXTREME
H3C
HPSW
IGNITENET
JUNIPER
MIKROTIK
MOXA-EDR
NET-SNMP
NETONIX
NETSCREEN
NTWS
OPTIX
PING3
PROCURVE
QTECH-OLT
RITTAL
SAF-INTEGRA-B
SYMBOL-WS
TB
UBNT-EDGESW
UBNT-AIRMAX
WESTERSTRAND
MIB Explorer
MIB browser shows all loaded MIB configurations, and allows to run SNMP walk on a selected node nodes. Node can be selected in browser by selecting Set node object… option in view menu or by opening MIB Explorer from node menu.
To run walk user should select line of tree from were will be requested all data. By walk will be requested all OID subtree of selected item.
After walk is done it’s results will shown in the table below.
- There are next options available for results:
Copy result line to clipboard
Copy name of selected line to clipboard
Copy type of selected line to clipboard
Copy value of selected line to clipboard
Export selected lines to CSV
Show selection in MIB tree
Create DCI from selected item
SNMP Trap Configuration
In this view is configured which event will be generated on exact trap OID and which OID data will be used as event parameter data.
In SNMP Trap mapping configuration window can be set next parameters:
Description of mapping rule
Trap OID or trap OID group with many subtree OIDs, matching OID will be given to event as $1 parameter
Event that will be generated on selected Trap OID
User Tag is special event attribute, that can be got by %u macros or as attribute of event class. This attribute can be set there or by script.
Parameters - OID values that will be passed to event as $2, $3, $4… parameters
In parameter configuration(Edit SNMP Trap Parameter Mapping) can be configured next things:
Description of a parameter
Select if parameter should be found by OID or by position in the message
Option not to convert value to hex string. If string contains not readable symbols(symbol number less than space symbol number) it will be automatically converted to hex string, this option is required to prevent auto conversion.
Default SNMP credentials
Default SNMP credentials can be set in SNMP Credentials configuration value will be checked.
. It does not matter if credentials are used for adding nodes manually, through network discovery or with the help of agent registration - in each caseUsing ifTable and ifXTable
There are 2 types of subtree that provides information about interfaces: old one
ifTable and new one ifXTable. Sometimes usage of new one creates error situations.
In this situation ifXTable can be disabled. This can be done in Properties of
node in Polling. Or this configuration can be set
globally by changing UseIfXTable
server configuration parameter.
Configure SNMP Proxy
If there is need to monitor nodes behind firewall using SNMP, there is option to install on one of the nodes NetXMS agent, open all required ports for this node and send SNMP request to other nodes in this subnet through installed agent.
Proxy configuration can be done wile creation of node of for already created node can be change in Communications tab of node properties. To configure proxy node select node in object selector SNMP Proxy.
Agent configuration
To enable SNMP proxy “EnableSNMPProxy” parameter should be set to “yes”.
Configure SNMP Trap Proxy
It is possible to proxy SNMP traps.
In this case as a destination of traps should be set the proxy node.
Agent configuration
To enable trap proxy “EnableSNMPTrapProxy” parameter should be set to “yes”.
Optionally can be configured also “SNMPTrapListenAddress” and “SNMPTrapPort”. Default values can be checked there: Master configuration file
Server configuration
By default traps are accepted only from known nodes. To accept all traps set “LogAllSNMPTraps” server configuration variable to 1.
To correctly send response for SNMPv3, it should be also configured the proxy node for the sender node. It is done in sender node properties in “Communications” tab, SNMP section.
Import MIB
MIB files (MIBs) describe structure of information transferred via SNMP. Every device can support multiple MIBs, some of them are standard and public, other can be proprietary and vendor specific. NetXMS uses compiled MIBs to allow you to select OID and see its description (for example when selecting SNMP data for DCI collection). You do not need to compile new MIBs if you are OK with direct input of OID.
Compiling MIBs
Change suffix of your new MIB file to .txt
Copy your MIB file to /usr/share/netxms/mibs
Use nxmibc binary to create a new compiled MIB file from all MIBs in directory. Add parameter -z for compressed output file.
nxmibc -d /usr/share/netxms/mibs -o /var/lib/netxms/netxms.mib
Parameters recognized by nxmibc:
nxmibc [options] source1 ... sourceN
Valid options:
-d <dir> : Include all MIB files from given directory to compilation
-o <file> : Set output file name (default is netxms.mib)
-P : Pause before exit
-s : Strip descriptions from MIB objects
-z : Compress output file
Troubleshooting
If nxmibc fails, it may be caused by syntax or import errors in your MIB. Try to check it with smilint (part of net-snmp package) and correct any errors on level 3.