SNMP Trap Handler for Network Configuration Management - Automated Response Guide

SNMP Trap Handler for Network Configuration Management - Automated Response Guide

Understanding how the SNMP Trap Handler processes network notifications and integrates with rConfig’s configuration management workflows is essential for effective deployment and operation. This guide explores the fundamental concepts, architecture, and operational principles underlying trap-driven network automation.

SNMP Trap Handler: Core Concepts and Architecture

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Understanding SNMP Traps

What Are SNMP Traps?

SNMP (Simple Network Management Protocol) traps are asynchronous notification messages sent by network devices to management systems when significant events occur. Unlike SNMP polling, where management systems periodically query devices for status information, traps are device-initiated messages providing immediate notification of state changes, errors, or noteworthy conditions.

Key Characteristics:

Asynchronous: Traps are sent immediately when events occur, not on a schedule. A router detecting a configuration change sends a trap within seconds, providing near real-time notification.

Unidirectional: Traps are “fire and forget” UDP messages. Devices send traps to configured destinations without expecting acknowledgment or confirmation of receipt. This lightweight protocol ensures trap transmission doesn’t impact device performance.

Event-Driven: Traps represent state changes or significant events: interface status changes, configuration modifications, authentication failures, hardware alerts, environmental conditions, or threshold violations.

Variable Content: Each trap contains an Object Identifier (OID) classifying the trap type, plus varbinds (variable bindings) providing event-specific data such as interface names, error codes, timestamps, or descriptive messages.

Trap Versions and Protocols

SNMPv1 Traps:

• Original trap specification, widely supported by legacy devices
• Fixed trap structure with generic and specific trap numbers
• Enterprise OID identifies device manufacturer or trap category
• Limited security (community string authentication only)

SNMPv2c Traps (also called SNMPv2 Trap PDU or Notification):

• Enhanced trap format with improved structure and flexibility
• Single trap OID identifies trap type (no separate generic/specific)
• Backward compatible with SNMPv1 in most implementations
• Community string authentication (same security model as v1)
• Most common in production networks: Balances functionality with broad device support

SNMPv3 Traps:

• Enterprise-grade security with authentication and encryption
• User-based security model (USM) with credential management
• Message integrity verification and privacy protection
• More complex configuration but significantly enhanced security
• Growing adoption in security-conscious environments

Tip

rConfig Trap Handler Support: The rConfig SNMP Trap Handler supports SNMPv1, SNMPv2c, and SNMPv3 traps. SNMPv2c is recommended for most deployments due to its widespread device support, simplified configuration, and adequate security for internal management networks.

Why Traps Matter for Configuration Management

Traditional configuration backup workflows operate on fixed schedules: hourly, daily, or weekly backups capture device configurations regardless of whether changes occurred. This approach creates gaps where configuration changes go undetected between backup cycles, generates unnecessary backups when nothing changed, and lacks context about what triggered configuration modifications.

Trap-driven configuration management transforms this model:

Immediate Change Detection: Configuration change traps notify rConfig the instant administrators modify device settings. No waiting for the next scheduled backup—changes are captured in real-time.

Event Correlation: Traps provide context about configuration changes: who made the change (if included in trap varbinds), when the change occurred (trap timestamp), what type of change (configuration commit, reload, specific command execution), and which device was affected.

Efficient Resource Usage: Backups triggered by actual configuration changes eliminate unnecessary backup jobs for unchanged devices, reducing network bandwidth consumption, storage utilization, and backup server load.

Audit Trail Enhancement: Combining trap data with configuration snapshots creates comprehensive audit records linking network events (trap notifications) with configuration states (backup snapshots) for compliance, troubleshooting, and change tracking.

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SNMP Trap Architecture in rConfig

System Components

The rConfig SNMP Trap Handler comprises multiple integrated components working together to receive, process, and act upon SNMP trap notifications.

Trap Listener Service

Function: Background daemon process listening on a UDP port for incoming SNMP trap messages from network devices.

Implementation: PHP-based service running under Supervisor process management, ensuring automatic startup, restart on failure, and operational monitoring.

Network Binding: Configurable to listen on specific IP addresses (single interface) or all interfaces (0.0.0.0), with adjustable port configuration (standard port 162 or custom ports).

Protocol Support: Accepts SNMPv1, SNMPv2c, and SNMPv3 traps, automatically detecting trap version and parsing accordingly.

Processing Pipeline: Upon trap reception, the listener extracts trap metadata (source IP, trap OID, timestamp), parses varbinds (variable bindings containing trap-specific data), and passes processed trap data to the filter matching engine.

Filter Matching Engine

Function: Evaluates received traps against configured filter rules to determine if and how traps should be processed.

Matching Logic:

1. OID Matching: Compares trap OID against each enabled filter’s configured trap OID
2. Vendor Matching: Optionally filters by device manufacturer for vendor-specific trap handling
3. Source Matching: Can limit matches to specific source IPs or subnet ranges (advanced configuration)
4. Priority Ordering: Processes filters in priority order, with first match determining action execution

Match Results:

• Match Found: Trap triggers configured actions, filter match recorded in logs
• No Match: Trap logged as “unmatched,” no actions executed
• Multiple Matches: First matching filter determines actions (subsequent matches ignored)

Cooldown Management: Tracks last execution time per filter per device, preventing action spam during trap storms by enforcing minimum intervals between action executions.

Action Execution Framework

Function: Executes configured automated responses when traps match filter rules.

Available Actions:

Download Configuration: Triggers immediate device backup through rConfig’s standard backup workflow. The action identifies the source device (via trap source IP or device resolution mapping), initiates SSH/Telnet connection using device credentials, retrieves current configuration, stores configuration file with trap-triggered timestamp, and updates device configuration history.

Send Email Notification: Generates email alerts containing trap details (source device, trap type, timestamp, relevant varbinds), sends to configured recipient lists, supports templated email content with trap data substitution, and includes links to device configuration history and trap log details.

Execute Webhook: POSTs trap data to external HTTP endpoints in JSON format, enables integration with ticketing systems (ServiceNow, Jira), monitoring platforms (Nagios, Zabbix, Prometheus), chat applications (Slack, Microsoft Teams), and custom automation frameworks.

Create Incident Ticket: Integrates with IT service management platforms to automatically open tickets for trap-triggered events, with configurable severity mapping, assignment rules, and ticket content templating.

Run Custom Script: Executes user-defined shell scripts or programs with trap data as input parameters, enabling unlimited extensibility for organization-specific automation workflows.

Action Sequencing: Multiple actions per filter execute in configured order, with each action’s success/failure logged independently for troubleshooting.

Device Resolution System

Function: Maps trap source IP addresses to rConfig device records, enabling device-specific actions and accurate reporting.

The Mapping Challenge: Network devices frequently send traps from IP addresses different from their management IP configured in rConfig. Common scenarios include:

• Devices sending traps from loopback interfaces for source stability
• Multi-homed devices with separate management and trap source interfaces
• Devices behind NAT where trap source IP is translated
• Virtual device contexts sharing physical hardware with different management IPs

Resolution Process:

1. Trap received from source IP (e.g., 192.168.100.1)
2. Handler checks device resolution table for matching entry
3. If mapping exists, associates trap with mapped rConfig device
4. If no mapping, trap logged with “No device” association
5. Device-specific actions (backups) execute against resolved device

Impact on Functionality:

• With Resolution: Actions execute on correct device, accurate reporting, complete audit trails
• Without Resolution: Actions fail (no target device), traps show “No device” in logs, statistics incomplete

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Trap Processing Workflow

End-to-End Trap Lifecycle

Understanding the complete journey from trap transmission to action execution clarifies how the system operates and aids troubleshooting.

Stage 1: Trap Generation and Transmission

Device Event Occurs: Network device experiences a significant event warranting notification: administrator executes configuration command, device processes configuration commit, internal monitoring detects state change, or threshold violation triggers alarm.

Trap Construction: Device SNMP agent constructs trap message including enterprise or notification OID identifying trap type, timestamp of event occurrence, varbinds containing event-specific data, and source identification information.

Network Transmission: Device sends UDP datagram containing trap to configured trap destination(s), typically on port 162 (standard) or custom configured port, with no acknowledgment expected or waited for.

Network Delivery: Trap traverses network infrastructure subject to standard UDP characteristics: no guaranteed delivery, no retransmission on loss, minimal network overhead, typically millisecond-scale transit time on healthy networks.

Stage 2: Trap Reception and Parsing

Listener Reception: rConfig trap handler daemon receives UDP datagram on configured port, extracts source IP address and port, and performs basic protocol validation.

Protocol Decoding: Handler identifies trap version (SNMPv1, v2c, v3), parses trap PDU according to version-specific structure, extracts trap OID and all varbinds, and validates community string (v1/v2c) or USM credentials (v3).

Data Extraction: System extracts structured trap data: source IP address, trap OID (full dotted notation), timestamp (local server time), varbind list (OID-value pairs), and community or security parameters.

Initial Logging: Trap recorded in database immediately upon successful parsing, ensuring no received trap is lost even if subsequent processing fails.

Stage 3: Device Resolution

Source IP Lookup: System queries device resolution table for entry matching trap source IP.

Mapping Application:

• If mapping exists: Associates trap with mapped rConfig device record, enables device-specific action execution
• If no mapping: Trap marked with “No device” association, device-specific actions cannot execute

Device Validation: For mapped devices, verifies device exists in current rConfig inventory, checks device is not disabled or archived, and confirms device accessibility if backup action pending.

Stage 4: Filter Matching

Filter Iteration: System retrieves all enabled trap filters, iterates through filters in priority order.

Match Evaluation: For each filter, system compares trap OID to filter’s configured trap OID (exact match required), validates vendor match if filter specifies vendor constraint, and checks source IP constraints if configured.

Cooldown Check: If OID and vendor match, system checks cooldown status: retrieves last execution timestamp for this filter and device, calculates time elapsed since last execution, and proceeds only if cooldown period has elapsed.

Match Outcome:

• Match Found: Records matched filter in trap log, proceeds to action execution, stops filter iteration (first match wins)
• No Match: After checking all filters, marks trap as “unmatched,” logs trap without actions, workflow ends

Stage 5: Action Execution

Action Queue Preparation: System retrieves configured actions from matched filter, orders actions by configured sequence, and prepares execution context with trap data and device information.

Sequential Execution: For each action in sequence:

Download Configuration Action:

• Validates device resolution (requires mapped device)
• Queues backup job in rConfig’s standard backup workflow
• Backup executes asynchronously (non-blocking)
• Success/failure logged independently of trap processing

Email Notification Action:

• Renders email template with trap data substitution
• Sends via configured SMTP server
• Logs delivery success/failure
• Non-critical failures don’t block subsequent actions

Webhook Action:

• Constructs JSON payload with trap data
• POSTs to configured endpoint URL
• Waits for response with timeout
• Logs HTTP response code and any errors

Custom Script Action:

• Executes script with trap data as environment variables or command arguments
• Captures script output and exit code
• Logs execution results
• Timeout protection prevents hung scripts from blocking handler

Error Handling: Each action executes independently with isolated error handling. Action failures are logged but don’t prevent subsequent actions from executing, ensuring maximum automation coverage even during partial failures.

Stage 6: Logging and Reporting

Database Recording: Complete trap record stored including all extracted data, device resolution status, filter match results, action execution outcomes, and processing timestamps.

Statistics Update: System updates real-time metrics: trap count increments, filter match/unmatch counters, action execution tallies, and processing time averages.

Dashboard Refresh: Updated statistics become visible in UI dashboard within refresh interval (typically 30 seconds).

Audit Trail: Complete trap lifecycle recorded for compliance reporting, troubleshooting analysis, and operational review.

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Filter Matching Logic Deep Dive

How Filters Evaluate Traps

Understanding filter matching logic is essential for creating effective trap filters and troubleshooting match failures.

OID Matching Rules

Exact Match Requirement: Trap OID must match filter OID character-for-character. Partial matches, wildcards, or prefix matching are not supported in current implementation.

Example:

• Filter OID: 1.3.6.1.4.1.9.9.43.2.0.1
• Trap OID: 1.3.6.1.4.1.9.9.43.2.0.1 → Match
• Trap OID: 1.3.6.1.4.1.9.9.43.2.0.2 → No match (last digit differs)
• Trap OID: 1.3.6.1.4.1.9.9.43.2.0 → No match (missing trailing .1)

Case Sensitivity: OIDs are numeric, so case is irrelevant. However, leading zeros or formatting differences can cause match failures.

Whitespace Handling: Leading/trailing whitespace in configured OID causes match failures. The system trims whitespace during filter creation to prevent this common error.

Vendor Matching

Optional Constraint: Vendor matching is supplementary to OID matching. If specified, both OID and vendor must match for filter to trigger.

Vendor Identification: Vendor determined from device record (for mapped traps) or trap OID enterprise prefix (for unmapped traps).

Use Case: Vendor matching enables different processing for similar traps from different manufacturers. Example: Configuration change trap OID may be similar across vendors, but actions differ (Cisco requires specific backup method vs. Juniper).

When Not Specified: If filter has no vendor constraint, any device sending matching trap OID triggers the filter regardless of manufacturer.

Priority and First-Match Behavior

Sequential Processing: Filters are evaluated in priority order (configurable in filter settings). First filter matching both OID and vendor (if specified) determines action execution.

No Multiple Matches: Once a filter matches, filter iteration stops. Lower-priority filters are not evaluated even if they would also match.

Implication for Filter Design:

• Place specific filters (detailed OID, specific vendor) higher in priority
• Place generic filters (common OIDs, no vendor constraint) lower in priority
• Avoid filter conflicts where multiple filters unintentionally match same trap

Example Priority Structure:

Priority 1: Cisco Config Change (specific) → Cisco-specific backup
Priority 2: Generic Config Change (any vendor) → Standard backup
Priority 3: All Traps (catch-all) → Log only

A Cisco config change trap matches Priority 1, executes Cisco-specific backup, and stops. It never reaches Priority 2 or 3.

Cooldown Period Mechanics

Purpose: Cooldown periods prevent action overload during trap storms, repeated events, or device instability by enforcing minimum time intervals between action executions for the same filter and device.

How Cooldown Works:

1. Initial Trap Match: First trap matching filter executes actions immediately, no cooldown restriction
2. Timestamp Recording: System records current timestamp as “last execution” for this filter-device pair
3. Subsequent Trap: Next trap matching same filter from same device checks cooldown status
4. Cooldown Check: Calculates elapsed time since last execution, compares to configured cooldown period
5. Cooldown Outcome:
   • Cooldown Active (elapsed < cooldown period): Trap logged but actions NOT executed
   • Cooldown Expired (elapsed ≥ cooldown period): Actions execute, timestamp updates

Cooldown Scope: Cooldown is per-filter, per-device. Different filters have independent cooldowns, same filter on different devices have independent cooldowns, and unmapped traps (no device) have global cooldown per filter.

Example Scenario:

Filter: "Config Change - Auto Backup"
Cooldown: 300 seconds (5 minutes)
Device: core-router-01

Timeline:
10:00:00 - Trap received → Actions execute (first occurrence)
10:02:00 - Trap received → Actions skipped (cooldown active, 2 min < 5 min)
10:04:00 - Trap received → Actions skipped (cooldown active, 4 min < 5 min)
10:06:00 - Trap received → Actions execute (cooldown expired, 6 min > 5 min)

Cooldown Configuration Guidelines:

Short Cooldowns (60-120 seconds):

• Critical alerts requiring immediate action
• Events unlikely to repeat rapidly
• High-value traps where every occurrence matters

Medium Cooldowns (300-600 seconds):

• Configuration backups (prevent backup storms)
• Routine notifications with moderate importance
• Events that may repeat but don’t require instant response

Long Cooldowns (900-1800 seconds):

• Informational traps for trending/analysis
• Low-priority events
• Traps known to repeat frequently during normal operation

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Integration with rConfig Workflows

Configuration Backup Triggering

Standard Backup Workflow: rConfig’s primary configuration backup mechanism operates on scheduled intervals: hourly, daily, or custom cron schedules execute backup jobs against device groups or entire inventory.

Trap-Triggered Backup Enhancement: SNMP trap integration adds event-driven backup capability complementing scheduled backups.

How Trap-Triggered Backups Work:

1. Trap Reception: Device sends configuration change trap to rConfig
2. Filter Match: Trap matches filter configured with “Download Configuration” action
3. Device Resolution: System resolves trap source to rConfig device record
4. Backup Job Creation: Handler creates backup job identical to scheduled backup
5. Job Queue: Backup job enters standard rConfig job queue
6. Execution: Backup workflow executes: connects to device, retrieves configuration, stores configuration file, updates configuration history
7. Verification: Backup success/failure logged in both trap log and device backup history

Advantages of Trap-Triggered Backups:

Immediate Capture: Configuration captured within seconds of change notification, not hours/days until next scheduled backup.

Change Correlation: Trap timestamp and backup timestamp create direct link between administrative action and configuration snapshot.

Selective Backups: Only changed devices backed up, not entire inventory, optimizing resource usage.

Audit Enhancement: Trap varbinds may contain user information, change description, or command details, enriching backup metadata for compliance auditing.

Complementary Approach: Trap-triggered backups complement, not replace, scheduled backups. Scheduled backups provide periodic verification and catch changes that don’t generate traps (manual console changes, changes from alternate management systems).

Event-Driven Automation Scenarios

Beyond configuration backups, trap-driven automation enables numerous operational workflows.

Scenario 1: Security Incident Response

Trigger: Authentication failure trap from critical infrastructure device

Automation Workflow:

1. Trap filter matches authentication failure OID
2. Actions execute:
   • Immediate configuration backup (preserve pre-incident state)
   • Email notification to security team
   • Webhook to SIEM platform (create security event)
   • Create high-priority incident ticket
   • Execute custom script to temporarily restrict device access

Outcome: Security team notified within seconds, configuration preserved for forensics, incident tracking initiated, automated containment measures applied.

Scenario 2: Change Management Compliance

Trigger: Configuration change trap during unauthorized maintenance window

Automation Workflow:

1. Filter matches config change trap
2. Custom script checks timestamp against approved change windows
3. If outside approved window:
   • Backup configuration (evidence capture)
   • Email alert to change management team
   • Create audit exception ticket
   • Webhook to compliance dashboard
   • Log detailed event for audit report

Outcome: Unauthorized changes detected immediately, complete audit trail created, compliance reporting automated, manual review triggered for policy violations.

Scenario 3: Proactive Problem Detection

Trigger: Environmental alarm trap (temperature, power supply, fan failure)

Automation Workflow:

1. Filter matches hardware alarm OID
2. Actions execute:
   • Configuration backup (preserve current state before potential failure)
   • Email alert to infrastructure team
   • Create maintenance ticket with priority based on alarm severity
   • Webhook to monitoring dashboard (update device health status)
   • Execute script to check device warranty status and spare availability

Outcome: Proactive maintenance initiated before complete failure, configuration safely backed up, resource planning automated, mean time to resolution reduced.

Scenario 4: Multi-Site Coordination

Trigger: Link down trap from WAN router at remote site

Automation Workflow:

1. Filter matches link down OID for WAN interfaces
2. Device resolution identifies specific remote site
3. Actions execute:
   • Backup configuration (document state during outage)
   • Email alert to network operations with site identifier
   • Webhook to monitoring system (update site connectivity status)
   • Custom script:
     • Checks backup link status
     • Initiates failover if primary link down
     • Updates routing configuration if needed
   • Create outage ticket with site information and impact assessment

Outcome: Site outage detected instantly, automated failover initiated, operations team notified with context, ticket tracking established, business continuity maintained.

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Best Practices for Trap-Driven Configuration Management

Filter Design Principles

Start Specific, Expand Gradually: Begin with filters for high-value, well-understood traps (configuration changes on critical devices). Validate effectiveness before expanding to additional trap types or device categories.

Document Filter Purpose: Use filter descriptions to record business rationale, expected trap frequency, action justification, and troubleshooting notes. Future administrators (including yourself six months later) will appreciate context.

Test Before Enabling: Create filters in disabled state, monitor logs to verify traps arrive and OIDs match, enable filter after confirming accuracy, and validate actions execute as intended.

Monitor Match Rates: Regularly review filter performance in dashboard. Filters with zero matches may have incorrect OIDs, obsolete trap types, or device configuration issues requiring investigation.

Implement Defense in Depth: Layer filters by priority: specific filters for known critical traps, moderate filters for common routine events, and catch-all filters for unknown traps (log-only action for visibility).

Device Resolution Strategy

Map Critical Devices First: Prioritize device resolution for infrastructure generating important traps: core routers and switches, firewalls and security devices, WAN and Internet edge equipment, and data center infrastructure.

Document Interface Context: Use mapping notes to record which interface sends traps, why mapping is necessary, and any relevant network context. Aids troubleshooting when trap sources change or devices are reconfigured.

Verify Mappings Work: After creating mappings, trigger test traps from devices and confirm logs show correct device association rather than “No device.”

Handle Multi-Homed Devices: Devices with multiple management interfaces may require multiple mappings if they send traps from different source IPs depending on routing or interface availability.

Review Unmapped Traps Regularly: Check dashboard and logs for persistent “No device” entries. These represent opportunities to improve device resolution coverage.

Action Configuration Guidelines

Order Actions by Criticality: Sequence actions with critical functions first (backups, ticket creation) followed by notifications (email, webhooks). If action execution fails mid-sequence, critical actions have already completed.

Balance Responsiveness and Load: Set cooldown periods considering trap frequency, action resource cost, and operational urgency. Start conservative (longer cooldowns), reduce if response time inadequate.

Test Actions Independently: Verify each action type works correctly outside trap context: manual device backups succeed, email notifications deliver, webhooks reach endpoints, and scripts execute without errors. Trap-triggered actions inherit these same dependencies.

Implement Graceful Degradation: Design actions to fail gracefully. Email delivery failure shouldn’t prevent backup execution. Webhook timeout shouldn’t block subsequent actions. Isolate action failures to minimize workflow disruption.

Monitor Action Execution: Regularly review trap logs for action failures. Persistent failures indicate configuration issues, connectivity problems, or resource constraints requiring resolution.

Operational Excellence

Establish Trap Baselines: Monitor trap volume, types, and sources during initial deployment to understand normal operational patterns. Deviations from baseline indicate device issues, configuration changes, or network problems.

Schedule Regular Reviews: Monthly or quarterly, review filter effectiveness (match rates, action success), device resolution coverage, trap volume trends, and action execution statistics. Adjust configurations based on findings.

Maintain Documentation: Keep current documentation of filter strategies, device resolution mappings, action workflows, and operational procedures. Documentation ensures consistent management across team members and simplifies troubleshooting.

Implement Change Control: Treat trap filter modifications and device resolution changes as configuration changes requiring approval, testing, and rollback plans. Document changes and maintain filter configuration history.

Plan for Scale: As trap volume grows, monitor system performance (processing time, database size, action queue depth). Implement log retention policies, database optimization, and resource scaling before performance degrades.

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Troubleshooting Common Scenarios

Traps Not Received

Symptom: Dashboard shows zero traps, no entries in logs, service appears online.

Diagnostic Approach:

Verify Network Connectivity:

• Confirm network devices can reach rConfig server IP
• Check firewalls allow UDP traffic on trap port (162 or custom)
• Test with tcpdump/wireshark on rConfig server:

  sudo tcpdump -i any -n port 162

• Send test trap from rConfig server itself (eliminates network variables)

Validate Device Configuration:

• Verify devices configured to send traps to correct IP address
• Confirm trap destination port matches rConfig listener port
• Check SNMP community string configuration on devices
• Ensure trap generation enabled for relevant event types

Confirm Service Operation:

• Verify trap handler service running via Supervisor
• Check service logs for startup errors or binding failures
• Validate port not already in use by another process

Filters Not Matching

Symptom: Traps appear in logs but show “No match” despite configured filters.

Diagnostic Approach:

Verify OID Accuracy:

• Compare trap OID in logs to filter OID configuration character-by-character
• Check for trailing zeros, extra digits, or truncation
• Reference vendor MIB documentation to confirm correct OID
• Use trap detail view to see exact OID received

Check Filter Status:

• Confirm filter enabled (not disabled)
• Verify filter not currently in cooldown period for this device
• Review filter priority—higher priority filter may be matching first

Validate Vendor Matching:

• If filter specifies vendor, confirm trap source device has correct vendor assigned
• Check device resolution mapping includes vendor information
• Try removing vendor constraint from filter to test OID-only matching

Test with Simplified Filter:

• Create test filter with only trap OID, no vendor or advanced constraints
• Disable cooldown for testing
• Trigger trap and observe if test filter matches

Actions Not Executing

Symptom: Filters match traps but configured actions don’t execute or fail.

Diagnostic Approach:

Review Trap Detail Log:

• View trap details in UI to see action execution results
• Look for error messages indicating specific failure causes
• Check action execution timestamps to confirm actions were attempted

Validate Prerequisites:

• Backup Action: Device must be mapped (device resolution), device must be reachable via SSH/Telnet, credentials must be current
• Email Action: SMTP configuration must be correct in rConfig settings, recipient addresses must be valid
• Webhook Action: Endpoint URL must be accessible from rConfig server, endpoint must accept POST requests with JSON payload
• Script Action: Script must exist at specified path, script must have execute permissions, script must exit cleanly (non-zero exit considered failure)

Test Actions Independently:

• Execute manual device backup to verify connectivity and credentials
• Send test email from rConfig to verify SMTP configuration
• Test webhook endpoint with curl from rConfig server command line
• Run custom scripts manually to verify functionality

Check Resource Availability:

• Verify adequate disk space for configuration backups
• Confirm database connectivity for logging and queuing
• Check network bandwidth adequate for action execution load

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Performance Considerations

Scalability Factors

Trap Volume: rConfig trap handler efficiently processes hundreds of traps per minute on typical hardware. Performance characteristics:

• 1-100 traps/minute: Negligible system impact, instant processing
• 100-1000 traps/minute: Light load, processing time < 100ms per trap
• 1000-5000 traps/minute: Moderate load, may require resource monitoring
• 5000+ traps/minute: High-volume environment, contact rConfig support for optimization guidance

Database Growth: Trap logs accumulate in database over time. Plan retention policies based on:

• Expected trap volume (traps per day × retention days)
• Database disk space allocation
• Compliance requirements for historical data
• Query performance with large datasets (100k+ trap records)

Action Execution Load: Actions consume system resources proportional to their complexity:

• Configuration backups: High resource cost (SSH connections, file storage)
• Email notifications: Low resource cost (SMTP transaction)
• Webhooks: Moderate resource cost (HTTP connection, network latency)
• Custom scripts: Variable cost (depends on script implementation)

Design action workflows considering overall system load and concurrency limitations.

Optimization Strategies

Filter Optimization:

• Limit total filter count to what’s operationally necessary (< 100 filters ideal)
• Disable obsolete filters rather than leaving enabled
• Use specific OIDs to minimize unnecessary matching attempts
• Implement appropriate cooldown periods to reduce action load

Device Resolution Efficiency:

• Create mappings only for devices sending traps requiring actions
• Don’t map all inventory if not necessary
• Regularly purge obsolete mappings for decommissioned devices

Log Management:

• Implement retention policy (default 90 days recommended)
• Archive historical logs to external storage if long-term retention required
• Regularly purge old trap records to maintain database performance
• Schedule maintenance tasks during low-traffic periods

Action Workflow Efficiency:

• Batch low-priority actions rather than executing immediately
• Use webhooks to offload processing to external systems
• Implement action queuing for high-volume environments
• Monitor action execution times and optimize slow operations

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Security Implications

Trap Source Validation

Trust Model: SNMP traps are UDP-based and easily spoofed. Implement defense-in-depth security:

Network-Level Filtering: Configure firewalls to accept trap traffic only from known device subnets or specific IP ranges. Implement ACLs on network infrastructure restricting trap sources.

Application-Level Validation: Use SNMPv3 with authentication and encryption for sensitive environments. Validate community strings (v1/v2c) match expected values. Implement source IP whitelist in trap handler configuration (advanced feature).

Monitoring for Abuse: Watch for unusual trap volume spikes (potential DoS attack or spoofing). Monitor for traps from unexpected sources (rogue devices or attackers). Alert on authentication failures in trap processing (invalid community strings).

Data Sensitivity in Traps

Information Disclosure Risk: SNMP traps may contain sensitive operational data:

• Configuration snippets revealing network architecture
• User accounts from authentication failure traps
• Internal IP addresses and topology information
• System performance metrics indicating vulnerabilities

Protection Strategies:

• Restrict access to trap logs to authorized personnel only
• Implement role-based access control for trap management interface
• Sanitize trap data before external integration (webhooks, tickets)
• Encrypt trap logs at rest if storing highly sensitive information
• Regularly audit trap data exports and external integrations

Action Execution Security

Automation Risk: Trap-triggered actions execute automatically without human review, creating potential security concerns:

Command Injection: Custom scripts receiving trap data as input must sanitize varbind content to prevent command injection attacks. Never execute untrusted trap content as shell commands.

Privilege Escalation: Actions execute with rConfig application privileges. Ensure rConfig account has minimum necessary permissions, avoid running trap handler as root, and implement separate service accounts for different action types if possible.

Audit Trail: Maintain comprehensive logging of all trap-triggered actions for security auditing and compliance. Log action initiation, execution results, any failures or errors, and user access to trap logs and filter configurations.

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Trap Storm Protection

What Are Trap Storms: Abnormal conditions causing devices to send excessive trap volumes: malfunctioning device generating thousands of traps per second, interface flapping rapidly triggering repeated link up/down traps, routing protocol instability causing continuous state change notifications, or misconfigured monitoring thresholds triggering constant threshold violations.

Impact of Trap Storms:

• Overwhelm trap handler processing capacity
• Fill database with duplicate or low-value trap records
• Trigger excessive automated actions (backup storms, email floods)
• Consume network bandwidth with unnecessary trap traffic
• Mask legitimate high-priority traps in noise

Built-in Protection Mechanisms:

Cooldown Periods: Primary defense against trap storms. Cooldown prevents same filter from executing actions repeatedly during storm conditions. Example: 5-minute cooldown means maximum one backup per device per filter every 5 minutes regardless of trap volume.

Source-Based Rate Limiting (Advanced Configuration): Limit trap processing rate per source IP address. Example: Accept maximum 10 traps per minute from any single source, discard excess. Prevents single malfunctioning device from overwhelming handler.

Action Queue Management: Actions execute asynchronously through queued jobs. Queue depth limits prevent unlimited action accumulation. When queue full, new actions defer until capacity available.

Operational Response to Trap Storms:

Identify Storm Source: Review dashboard “Top Sources by Trap Volume” to identify devices sending excessive traps. Check trap logs for repeated trap types from specific devices.

Temporary Mitigation: Disable filter causing action overload (stops automated actions while preserving trap logging). Add firewall rule to temporarily block trap traffic from malfunctioning device. Increase cooldown period for affected filter until device issue resolved.

Root Cause Resolution: Investigate why device generating trap storm (device malfunction, configuration error, environmental issue). Correct underlying problem rather than permanently suppressing traps. Re-enable filters after device stability confirmed.

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Support with rConfig Vector

As of rConfig V8.0.0, the SNMP Trap Handler does not include support for rConfig Vector. We expect to add this functionality in a future release.

Related Documentation

• Device Connectivity Process - Understanding backup workflows triggered by traps
• CLI Commands - SNMP trap CLI management commands
• SNMP Polling Concepts - Complementary SNMP functionality
• Device Management Fundamentals - Device resolution and mapping
• System Logs - Troubleshooting trap processing issues

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