What is an SNMP Trap?
SNMP Trap is a notification issued by a managed device when a significant event occurs. SNMP traps are the primary means of receiving notification of abnormal (or normal) events from SNMP-enabled devices. SNMP trap can contain a wide array of information such as port failures, link failures, access violations, power outages, paper jams, hard drive failures etc. This makes receiving and interpreting the traps essential to the proper management of a network.
Traps, like regular SNMP variables, are defined in MIB (Management Information Base) files. They are defined as a set of SNMP variables contained in (or referenced by) an OID (Object Identifier).
How to Select an SNMP Trap Management System
Here's a handy checklist of essential features you should look for in SNMP trap management. Print this checklist out and use it to rate the SNMP trap managers you're evaluating. If an SNMP trap manager can't meet these basic requirements, cross it off your list.
- Complete Alarm collection and device management: Don't settle for a limited SNMP trap management system. Get multi protocol support for every monitoring device in your network in addition to SNMP.
- Alarm presentation and notification: Send detailed alarm descriptions and correction instructions to NOC and field techs via SMS (Mobile phone) notifications and emails. SMS and e-mail notifications let your field techs respond to alarms while they're still in the field, speeding repairs and reducing windshield time. Look for an SNMP trap manager system with SMS support, which can send detailed alarm notifications to alpha pagers, cell phones, and PDAs.
- Alarm sorting and analysis: Make sense of alarm cascades with automatic intelligent alarm sorting, filtering and processing.
- Maintain a list of standing alarms:
SNMP trap management must maintain a list of standing alarms and not just log newly reported or acknowledged traps. Imagine what would happen to your network if a system operator acknowledged an alarm, and then failed to correct the alarm condition. Who would know the alarm was still standing? No one!
- Detailed, precise alarm descriptions:
SNMP alarm monitoring systems should record the time, location, severity, and a precise description of alarm events
- Nuisance alarm filtering: Even the best NOC staff stops taking alarms seriously if they're bombarded with status alerts, oscillating conditions, and unimportant alarms. Look for an SNMP trap manager system that filters these out.
- Alarm sorting: A large, complex network can create a cascade of alarms. Some are unimportant, but others are critical. Look for an SNMP trap manager system that can automatically sort and prioritize this flood of information for you.
- Alarm correction instructions: Detailed instructions included in alarm notifications ensure that system operators, without extra training, will know precisely what to do and who to call if an alarm happens.
SNMP Trap Handling with NetDecision
NetDecision TrapVision is capable of receiving the traps, interpreting them, and displaying notification messages in a graphical display. The people at the management center viewing the display are then alerted to the problem.
TrapVision has the capability to handle SNMP traps in various ways depending on the trap type and trap variables values:
- TrapVision can receive SNMPv1, SNMPv2c and SNMPv3 TRAP notification messages and SNMPv2c and SNMPv3 INFORM notification messages;
- The TrapVision main window acts as console viewer displaying real-time information about received traps;
- TrapVision allows the user to assign severity levels and colors to SNMP traps in order to indicate their importance and provide a better overview of received SNMP notifications displayed in the main window.
- TrapVision allows the user to create filtering and processing rules based on originator IP address, Enterprise ID, variable values;
- TrapVision provides a set of preconfigured Trap handlers enabling the following actions to be automatically executed upon trap receiving:
- forward Trap to one or more destinations (each specified by IP address and port);
- send e-mail to one or more recipients;
- log trap data to a log file;
- store trap data in a database via ODBC;
- execute any external application or command;
- enable audible alarm;
- send syslog message to one or more syslog servers;
- create task in MS Outlook;
- send SMS via GSM mobile phone;
- invoke web service;
- write to Windows Event log.
- TrapVision allows the user to create new trap handlers or modify existing ones to implement custom handling procedures;
- TrapVision has built-in PDU tracing functionality which allows the user to catch, decode and view the SNMP data packet elements down to any single detail in decoded ASN.1 tree;
- TrapVision allows the user to create and view web reports (integration with Remote Management Console);
- TrapVision can be managed remotely using Remote Management Console;
- Quick Reports window provides user with a simple pie chart representing a summary information about traps currently listed in the main view;
- TrapVision automatically clears aged (outdated) traps based on user defined rules;
- TrapVision resolves IP addresses using DNS;
- TrapVision supports automatic acknowledgement of traps;
- TrapVision allows the user to group traps.
Remote Trap Management
Due to its unique trap handling capability, TrapVision is an ideal tool for the first-stage handling of the SNMP trap traffic. TrapVision can manage SNMP traps at remote sites, forwarding only the important traps to the high-level management console application, possibly minimizing the traffic.
NetDecision Remote Management Console is an application, that allows the user to monitor multiple instances of TrapVision and/or LogVision running on local or remote servers. With Remote Management Console, you can easily connect to another computer running TrapVision or LogVision application. All you need is network access and permissions to connect to remote server.
Remote Management Console provides:
- TrapVision/LogVision Servers monitoring;
- Maintenance mode management (Tech on site);
- Web snapshot view;
- Custom trap reports in HTML format.
See the example of the Trap Management solution in the following article: SNMP Trap management for ADC Digivance® RF transport products