- play_arrow Overview
- play_arrow Operation, Administration, and Management Features
- play_arrow Ethernet OAM and Connectivity Fault Management for Routers
- Introduction to OAM Connectivity Fault Management (CFM)
- Configure Connectivity Fault Management (CFM)
- CFM Action Profile
- Ethernet Local Management Interface
- CFM Support for CCC Encapsulated Packets
- Configure Unified ISSU for 802.1ag CFM
- CFM Monitoring between CE and PE Devices
- Configure Continuity Check Messages
- Example: Configure Ethernet CFM on Physical Interfaces
- Example: Configure Ethernet CFM on Bridge Connections
- Example: Configure Ethernet CFM over VPLS
- play_arrow Link Fault Management for Routers
- play_arrow Ethernet OAM Link Fault Management for Switches
- play_arrow Ethernet OAM Connectivity Fault Management for Switches
- play_arrow Ethernet Frame Delay
- Ethernet Frame Delay Measurements on Switches
- Configure MEP Interfaces on Switches to Support Ethernet Frame Delay Measurements (CLI Procedure)
- Configure One-Way Ethernet Frame Delay Measurements on Switches (CLI Procedure)
- Configure an Iterator Profile on a Switch (CLI Procedure)
- Trigger an Ethernet Frame Delay Measurement Session on a Switch
- Configure Two-Way Ethernet Frame Delay Measurements on Switches (CLI Procedure)
- play_arrow Ethernet Service OAM (ITU-TY.1731) for Routers
- ITU-T Y.1731 Ethernet Service OAM Overview
- Configure Ethernet Frame Delay Measurement Sessions
- Configuring MEP Interfaces to Support Ethernet Frame Delay Measurements
- Configure Ethernet Frame Loss Measurement
- Configure an Iterator Profile
- Configure Ethernet Synthetic Loss Measurements
- Ethernet Alarm Indication
- Inline Transmission Mode
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- play_arrow Remote Network Monitoring (RMON) with SNMP Alarms and Events
- play_arrow Accounting Options
- play_arrow Monitoring Options
- play_arrow Interface Alarms
- play_arrow IP Monitoring
- play_arrow sFlow Monitoring Technology
- play_arrow Adaptive Sampling for Routers and Switches
- play_arrow Packet Flow Accelerator Diagnostics Software
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- play_arrow Monitoring Common Security Features
- play_arrow Performance Management
- play_arrow Port Mirroring
- play_arrow Port Mirroring and Analyzers
- Port Mirroring and Analyzers
- Configuring Port Mirroring and Analyzers
- Configuring Port Mirroring Instances
- Configuring Port Mirroring on Physical Interfaces
- Configuring Port Mirroring on Logical Interfaces
- Configuring Port Mirroring for Multiple Destinations
- Configuring Port Mirroring for Remote Destinations
- Configuring Port Mirroring Local and Remote Analysis
- 1:N Port Mirroring to Multiple Destinations on Switches
- Example: Configure Port Mirroring with Family any and a Firewall Filter
- Monitoring Port Mirroring
- Configure Packet Mirroring with Layer 2 Headers for Layer 3 Forwarded Traffic
- Troubleshooting Port Mirroring
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- play_arrow System Log Messages
- play_arrow Network Management and Troubleshooting
- Compressing Troubleshooting Logs from /var/logs to Send to Juniper Networks Technical Support
- Monitoring and Troubleshooting
- Troubleshooting System Performance with Resource Monitoring Methodology
- Configuring Data Path Debugging and Trace Options
- Using MPLS to Diagnose LSPs, VPNs, and Layer 2 Circuits
- Using Packet Capture to Analyze Network Traffic
- On-Box Packet Sniffer Overview
- Troubleshooting Security Devices
- play_arrow Configuration Statements and Operational Commands
SNMP Architecture and SNMP MIBs Overview
SNMP Architecture
A typical SNMP implementation includes three components:
Network Management System (NMS)—A combination of hardware (devices) and software (the SNMP manager) used to monitor and administer a network. The manager polls the devices on your network as you specify for information about network connectivity, activity, and events.
Managed device—A managed device (also called a network element) is any device on a network managed by the NMS. Routers and switches are common examples of managed devices.
SNMP agent—The SNMP agent is the SNMP process that resides on the managed device and communicates with the NMS. The SNMP agent exchanges network management information with the SNMP manager software running on an NMS, or host. The agent responds to requests for information and actions from the manager. The agent also controls access to the agent’s MIB, the collection of objects that can be viewed or changed by the SNMP manager.
This topic contains the following sections:
SNMP MIBs
You can store SNMP data in a highly structured, hierarchical format known as a Management Information Base (MIB). A MIB defines managed objects in a network device.
The MIB structure is based on a tree structure and defines a grouping of objects into related sets. Each object in the MIB is associated with an object identifier (OID), which names the object. The “leaf” in the tree structure is the actual managed object instance, which represents a resource, event, or activity that occurs in your network device.
MIBs are either standard or enterprise-specific. For more information, see Table 1.
| Standard MIBs | Enterprise-specific MIBs |
|---|---|
| Created by the Internet Engineering Task Force (IETF) and documented in various RFCs. Depending on the vendor, many standard MIBs are delivered with the NMS software. You can also download the standard MIBs from the IETF website, www.ietf.org, and compile them into your NMS, if necessary. | Developed and supported by a specific equipment manufacturer. If your network contains devices that have enterprise-specific MIBs, you must obtain them from the manufacturer and compile them into your network management software. |
For a list of standard supported MIBs, see Standard SNMP MIBs Supported by Junos OS. | For a list of Juniper Networks enterprise-specific supported MIBs, see Enterprise-Specific SNMP MIBs Supported by Junos OS. |
SNMP Manager and Agent Authentication and Communication
SNMP uses a basic form of authentication called community strings to control access between a manager and remote agents. Community strings are administrative names used to group collections of devices (and the agents running on them) into common management domains. If a manager and an agent share the same community, they can talk to one another. Many people associate SNMP community strings with passwords and keys because the jobs they do are similar. As a result, SNMP communities are traditionally referred to as strings.
Communication between the agent and the manager occurs in one of the following forms:
Get,GetBulk, andGetNextrequests—The manager requests information from the agent; the agent returns the information in aGetresponse message.Setrequests—The manager changes the value of a MIB object controlled by the agent; the agent indicates status in aSetresponse message.Trapsnotification—The agent sends traps to notify the manager of significant events that occur on the network device.
SNMP Traps and Informs
Routers can send notifications to SNMP managers when significant events occur on a network device, most often errors or failures. You can send SNMP notifications as traps or inform requests.
SNMP traps are unconfirmed notifications and SNMP informs are confirmed notifications.
SNMP traps are either standard or enterprise-specific. For more information, see Table 2.
| Standard Traps | Enterprise-specific Traps |
|---|---|
Created by the IETF and documented in various RFCs. The standard traps are compiled into the network management software. You can also download the standard traps from the IETF website, www.ietf.org. | Developed and supported by a specific equipment manufacturer. If your network contains devices that have enterprise-specific traps, you must obtain them from the manufacturer and compile them into your network management software. |
For more information about standard traps supported by the Junos OS, see Standard SNMP Traps Supported on Devices Running Junos OS. | For more information about enterprise-specific traps supported by the Junos OS, see Enterprise-Specific SNMP Traps Supported by Junos OS. For information about system logging severity levels for SNMP traps, see Understand SNMP Implementation in Junos OS. |
With traps, the receiver does not send any acknowledgment when it receives a trap, and the sender cannot determine if the trap was received. To increase reliability, SNMP informs are supported in SNMPv3. An SNMP manager that receives an inform acknowledges the message with a response. For information about SNMP informs, see Configure SNMP Informs.
