What is SNMP; for what purposes is it used in TR7?

Short answer

SNMP (Simple Network Management Protocol) is the standard management protocol used for monitoring network devices from a central monitoring system (NMS) (RFC 3411). In TR7, it is used in two directions. When an event occurs, TR7 sends an SNMP trap to the NMS on its own: the target address, the version and the community are defined once in the SNMP Settings section, and the events for which a trap is sent are selected with the SNMP Trap channel in the notification profiles. For the NMS to be able to query TR7 at regular intervals, on the other hand, an SNMP agent runs on the device; its access, allowed networks and versions are defined in the SNMP section of the Management Access screen (default port 161, read-only access). For the NMS to be able to resolve the TR7-specific values, the MIB file is downloaded from the SNMP Files row on the same screen.

Where It Is Used in TR7

Where	Field / label	What for
Settings → General Settings → Notification Management → SNMP settings	Route Table, SNMP Version, SNMP Community Name, SNMP IP:Port	The NMS target the traps are sent to; all modules use this target
Settings → General Settings → Notification Management → Notifications → Add	Notification Action → SNMP trap	Sending traps on device events (CPU, memory, disk, VIP, interface…)
Load Balancer → Profiles → Notifications	SNMP Trap	Traps on vService and Backend Service events
Left Monitor Panel → WAF-Protected vServices → vService → WAF Management → Notifications	SNMP Notification	Traps on WAF threshold notifications
Left Monitor Panel → Bot/DDoS Protected vServices → vService → Bot/DDoS Management → Notifications	SNMP Notification	Traps on Bot/DDoS notifications
AGS → Integrations → Notification Profiles	SNMP Notification	Traps on AGS threshold and engine status alarms
Settings → Device Management → Management Access → Edit → SNMP	SNMP (IP and port, default 161), SNMP Allowed Networks, SNMPd V1, SNMPd V2, SNMPd V3	Having the device queried as an SNMP agent
Settings → Device Management → Management Access	SNMP Files → SNMP MIBS (tr7-mibs.zip)	Resolving the TR7-specific OIDs on the NMS

• Difference between trap and agent: What is the difference between SNMP Trap and the SNMP agent? · Versions: What is the difference between SNMP v1, v2c and v3? · Community: What is an SNMP community?
• In a cluster, the SNMP settings and the Management Access settings are synchronized to the peer device; each device sends traps separately for its own events, and the agent of each device is queried separately.

Common Misconceptions

• "A single setting is enough to turn on SNMP." Sending traps (Notification Management → SNMP settings and the notification channels) and querying the device (Management Access → SNMP) are configured separately, on separate screens.
• "A trap is sent even without a notification channel being selected." A trap is sent only if the SNMP channel is on in a notification profile or on a module notification screen, a target is defined in SNMP settings and SNMP version v1 or v2c is selected; details: What is the difference between SNMP v1, v2c and v3?
• "Settings can be changed through the SNMP agent." The TR7 SNMP agent gives only read access; configuration is done from the interface, from WEB-CLI or from the REST API.

How it is done in the documentation

• Notification Management · SNMP Settings
• Management Access · SNMP
• Management Access · SNMP & Grafana Files

Related questions

• Can I get notified when a vService goes down; which channels are available (SNMP, e-mail, SMS)?
• What are the notification channels (UI, e-mail, SMS, SNMP)?
• What is Notification Management; how do the notification profile, Contact Groups and channels come together?