Logging, SNMP, and Telemetry

System Logging (Syslog)

You can configure system logging to record system events, track configuration changes, and troubleshoot issues.

You can enable system logging at the [edit system syslog] hierarchy level.

Key logging commands and features include:

• Log messages—Use show log messages in operational mode to display system log messages.
• Firewall filter logging—Apply log or syslog actions in firewall filters to log packet headers or send information to syslog server. The log action buffers information in the Packet Forwarding Engine (view with show firewall log), while syslog writes to system log files.
• Queue and interface monitoring—The logs for hierarchical scheduling changes, virtual output queue (VOQ) stats, or interface sets appear in the syslog. While capturing these logs require configuration, significant queue events are automatically logged. Use show interfaces queue, show interfaces interface-set queue, or show interfaces voq to see related data.
• Other Contexts—Logs also captures information such as equal-cost multipath (ECMP) flow changes, tunnel interface stats, and physical interface events.

For more information, see Overview of System Logging.

SNMP

You can use SNMP to monitor and administer a device, manage interfaces, monitor firewall filters, and leverage other features through SNMP MIBs. For more information on SNMP, see SNMP Architecture and SNMP MIBs Overview.

You can enable SNMP at the [edit snmp] hierarchy level.

Key SNMP capabilities include:

• Interface monitoring—Use SNMP to query physical interface properties, see the interface index using the command show interfaces, and walk the MIB by running snmpwalk on a management server.
• Firewall filter monitoring—SNMP can monitor firewall filter match conditions applied on Layer 2 switched packets in bridge domains with IRB interfaces. For example, SNMP monitors match conditions such as Internet Control Message Protocol (ICMP) types or codes, Differentiated Services code point (DSCP) values, and Ethernet types.
• Aggregated interfaces—SNMP queries can retrieve MAC addresses and bundle status.

Telemetry

Telemetry on ACX7000 routers provides real-time network data streaming through RPC (gRPC) to monitor systems, providing faster and more scalable network monitoring compared to SNMP.

Telemetry streams operational data from the forwarding plane to external collectors, enabling you to monitor traffic patterns, utilization, and congestion without polling. Telemetry uses model-driven sensors to export structured metrics over telemetry transports, enabling scalable, high-frequency visibility for performance analysis, troubleshooting, and capacity planning across your network. For more information, see Understanding Junos Telemetry.

To enable this feature, you need to ensure:

• Junos Telemetry Interface is available.

• gRPC service is available.

• OpenConfig for Junos OS Evolved is installed.

Here is a sample configuration to enable telemetry to stream data to a collector:

• grpc: Protocol used for telemetry streaming.

• remote-address: Telemetry collector server.

• remote-port: Port used by the collector.

Here is a sample configuration to set up telemetry sensors (example, interface statistics):

This configuration enables telemetry to stream:

• Interface status

• Traffic counters

• Error statistics