Implementing SNMP on the Cisco IOS XR Software
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Contents
- Implementing SNMP on the Cisco IOS XR Software
- Prerequisites for Implementing SNMP
- Restrictions for SNMP Use on Cisco IOS XR Software
- Information About Implementing SNMP
- SNMP Functional Overview
- SNMP Manager
- SNMP Agent
- MIB
- SNMP Notifications
- SNMP Versions
- Comparison of SNMPv1, v2c, and v3
- Security Models and Levels for SNMPv1, v2, v3
- SNMPv3 Benefits
- SNMPv3 Costs
- User-Based Security Model
- View-Based Access Control Model
- MIB Views
- Access Policy
- IP Precedence and DSCP Support for SNMP
- How to Implement SNMP on Cisco IOS XR Software
- Configuring SNMPv3
- Configuring SNMP Trap Notifications
- Setting the Contact, Location, and Serial Number of the SNMP Agent
- Defining the Maximum SNMP Agent Packet Size
- Changing Notification Operation Values
- Setting IP Precedence and DSCP Values
- Displaying SNMP Context Mapping
- Configuring MIB Data to be Persistent
- Configuring LinkUp and LinkDown Traps for a Subset of Interfaces
- Configuration Examples for Implementing SNMP
- Configuring SNMPv3: Examples
- Configuring Trap Notifications: Example
- Setting an IP Precedence Value for SNMP Traffic: Example
- Setting an IP DSCP Value for SNMP Traffic: Example
- Additional References
Implementing SNMP on the Cisco IOS XR Software
Simple Network Management Protocol (SNMP) is an application-layer protocol that provides a message format for communication between SNMP managers and agents. SNMP provides a standardized framework and a common language used for the monitoring and management of devices in a network.
This module describes the new and revised tasks you need to implement SNMP on your Cisco IOS XR network.
For detailed conceptual information about SNMP on the Cisco IOS XR software and complete descriptions of the SNMP commands listed in this module, see Related Documents. To locate documentation for other commands that might appear in the course of performing a configuration task, search online in Cisco IOS XR Commands Master List for the Cisco XR 12000 Series Router.
Table 1 Feature History for Implementing SNMP on Cisco IOS XR Software Release
Modification
Release 3.2
This feature was introduced.
Release 3.3.0
No modification.
Release 3.4.0
No modification.
Release 3.5.0
No modification.
Release 3.6.0
Support was added for encrypted community strings.
Support was added for setting IPv4 precedence and DSCP values.
The clear snmp counters command was added.
Release 3.7.0
No modification.
Release 3.8.0
Support was added for SNMP contexts.
Release 3.9.0
Support was added for 3DES and AES encryption.
The ability to preserve ENTITY-MIB and CISCO-CLASS-BASED-QOS-MIB data was added.
This module contains the following topics:
- Prerequisites for Implementing SNMP
- Restrictions for SNMP Use on Cisco IOS XR Software
- Information About Implementing SNMP
- How to Implement SNMP on Cisco IOS XR Software
- Configuration Examples for Implementing SNMP
- Additional References
Related Tasks
Prerequisites for Implementing SNMP
You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Restrictions for SNMP Use on Cisco IOS XR Software
SNMP outputs are only 32-bits wide and therefore cannot display any information greater than 232. 232 is equal to 4.29 Gigabits. Note that a 10 Gigabit interface is greater than this and so if you are trying to display speed information regarding the interface, you might see concatenated results.
Information About Implementing SNMP
- SNMP Functional Overview
- SNMP Notifications
- SNMP Versions
- SNMPv3 Benefits
- SNMPv3 Costs
- IP Precedence and DSCP Support for SNMP
SNMP Functional Overview
SNMP Manager
The SNMP manager is the system used to control and monitor the activities of network hosts using SNMP. The most common managing system is called a network management system (NMS). The term NMS can be applied to either a dedicated device used for network management, or the applications used on such a device. A variety of network management applications are available for use with SNMP. These features range from simple command-line applications to feature-rich graphical user interfaces (such as the CiscoWorks 2000 line of products).
SNMP Agent
The SNMP agent is the software component within the managed device that maintains the data for the device and reports these data, as needed, to managing systems. The agent and MIB reside on the router. To enable the SNMP agent, you must define the relationship between the manager and the agent.
MIB
The Management Information Base (MIB) is a virtual information storage area for network management information, which consists of collections of managed objects. Within the MIB there are collections of related objects, defined in MIB modules. MIB modules are written in the SNMP MIB module language, as defined in STD 58, RFC 2578, RFC 2579, and RFC 2580. Note that individual MIB modules are also referred to as MIBs; for example, the Interfaces Group MIB (IF-MIB) is a MIB module within the MIB on your system.
The SNMP agent contains MIB variables whose values the SNMP manager can request or change through Get or Set operations. A manager can get a value from an agent or store a value into that agent. The agent gathers data from the MIB, the repository for information about device parameters and network data. The agent can also respond to manager requests to get or set data.
Figure 1 illustrates the communications relationship between the SNMP manager and agent. A manager can send the agent requests to get and set MIB values. The agent can respond to these requests. Independent of this interaction, the agent can send unsolicited notifications (traps) to the manager to notify the manager of network conditions.
Related Concepts
SNMP Notifications
A key feature of SNMP is the ability to generate notifications from an SNMP agent. These notifications do not require that requests be sent from the SNMP manager. On Cisco IOS XR software, unsolicited (asynchronous) notifications can be generated only as traps. Traps are messages alerting the SNMP manager to a condition on the network. Notifications can indicate improper user authentication, restarts, the closing of a connection, loss of connection to a neighbor router, or other significant events.
Note
Inform requests (inform operations) are not supported in Cisco IOS XR software.
Traps are less reliable than informs because the receiver does not send any acknowledgment when it receives a trap. The sender cannot determine if the trap was received. An SNMP manager that receives an inform request acknowledges the message with an SNMP response protocol data unit (PDU). If the manager does not receive an inform request, it does not send a response. If the sender never receives a response, the inform request can be sent again. Thus, informs are more likely to reach their intended destination.
However, traps are often preferred because informs consume more resources in the router and in the network. Unlike a trap, which is discarded as soon as it is sent, an inform request must be held in memory until a response is received or the request times out. Also, traps are sent only once, and an inform may be retried several times. The retries increase traffic and contribute to a higher overhead on the network. Thus, traps and inform requests provide a trade-off between reliability and resources.
SNMP Versions
Cisco IOS XR software supports the following versions of SNMP:
- Simple Network Management Protocol Version 1 (SNMPv1)
- Simple Network Management Protocol Version 2c (SNMPv2c)
- Simple Network Management Protocol Version 3 (SNMPv3)
Both SNMPv1 and SNMPv2c use a community-based form of security. The community of managers able to access the agent MIB is defined by an IP address access control list and password.
SNMPv2c support includes a bulk retrieval mechanism and more detailed error message reporting to management stations. The bulk retrieval mechanism supports the retrieval of tables and large quantities of information, minimizing the number of round-trips required. The SNMPv2c improved error handling support includes expanded error codes that distinguish different kinds of error conditions; these conditions are reported through a single error code in SNMPv1. Error return codes now report the error type. Three kinds of exceptions are also reported: no such object exceptions, no such instance exceptions, and end of MIB view exceptions.
SNMPv3 is a security model. A security model is an authentication strategy that is set up for a user and the group in which the user resides. A security level is the permitted level of security within a security model. A combination of a security model and a security level will determine which security mechanism is employed when an SNMP packet is handled. See Table 1 for a list of security levels available in SNMPv3. The SNMPv3 feature supports RFCs 3411 to 3418.
You must configure the SNMP agent to use the version of SNMP supported by the management station. An agent can communicate with multiple managers; for this reason, you can configure the Cisco IOS-XR software to support communications with one management station using the SNMPv1 protocol, one using the SNMPv2c protocol, and another using SMNPv3.
Comparison of SNMPv1, v2c, and v3
SNMP v1, v2c, and v3 all support the following operations:
get-request—Retrieves a value from a specific variable.
get-next-request—Retrieves the value following the named variable; this operation is often used to retrieve variables from within a table. With this operation, an SNMP manager does not need to know the exact variable name. The SNMP manager searches sequentially to find the needed variable from within the MIB.
get-response—Operation that replies to a get-request, get-next-request, and set-request sent by an NMS.
set-request—Operation that stores a value in a specific variable.
trap—Unsolicited message sent by an SNMP agent to an SNMP manager when some event has occurred.
Table 1 identifies other key SNMP features supported by the SNMP v1, v2c, and v3.
Table 2 SNMPv1, v2c, and v3 Feature Support Feature
SNMP v1
SNMP v2c
SNMP v3
Get-Bulk Operation
No
Yes
Yes
Inform Operation
No
Yes (No on the Cisco IOS XR software)
Yes (No on the Cisco IOS XR software)
64 Bit Counter
No
Yes
Yes
Textual Conventions
No
Yes
Yes
Authentication
No
No
Yes
Privacy (Encryption)
No
No
Yes
Authorization and Access Controls (Views)
No
No
Yes
Security Models and Levels for SNMPv1, v2, v3
The security level determines if an SNMP message needs to be protected from disclosure and if the message needs to be authenticated. The various security levels that exist within a security model are as follows:
- noAuthNoPriv—Security level that does not provide authentication or encryption.
- authNoPriv—Security level that provides authentication but does not provide encryption.
- authPriv—Security level that provides both authentication and encryption.
Three security models are available: SNMPv1, SNMPv2c, and SNMPv3. The security model combined with the security level determine the security mechanism applied when the SNMP message is processed.
Table 1 identifies what the combinations of security models and levels mean.
Table 3 SNMP Security Models and Levels Model
Level
Authentication
Encryption
What Happens
v1
noAuthNoPriv
Community string
No
Uses a community string match for authentication.
v2c
noAuthNoPriv
Community string
No
Uses a community string match for authentication.
v3
noAuthNoPriv
Username
No
Uses a username match for authentication.
v3
authNoPriv
HMAC-MD5 or HMAC-SHA
No
Provides authentication based on the HMAC1-MD52 algorithm or the HMAC-SHA3.
v3
authPriv
HMAC-MD5 or HMAC-SHA
DES
Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides DES4 56-bit encryption in addition to authentication based on the CBC5 DES (DES-56) standard.
v3
authPriv
HMAC-MD5 or HMAC-SHA
3DES
Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides 168-bit 3DES6 level of encryption.
v3
authPriv
HMAC-MD5 or HMAC-SHA
AES
Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides 128-bit AES7 level of encryption.
1 Hash-Based Message Authentication Code2 Message Digest 53 Secure Hash Algorithm4 Data Encryption Standard5 Cipher Block Chaining6 Triple Data Encryption Standard7 Advanced Encryption StandardUse of 3DES and AES encryption standards requires that the security package (k9sec) be installed. For information on installing software packages, see Upgrading and Managing Cisco IOS XR Software.
SNMPv3 Benefits
SNMPv3 provides secure access to devices by providing authentication, encryption and access control. These added security benefits secure SNMP against the following security threats:
- Masquerade—The threat that an SNMP user may assume the identity of another SNMP user to perform management operations for which that SNMP user does not have authorization.
- Message stream modification—The threat that messages may be maliciously reordered, delayed, or replayed (to an extent that is greater than can occur through the natural operation of a subnetwork service) to cause SNMP to perform unauthorized management operations.
- Disclosure—The threat that exchanges between SNMP engines could be eavesdropped. Protecting against this threat may be required as a matter of local policy.
In addition, SNMPv3 provides access control over protocol operations on SNMP managed objects.
SNMPv3 Costs
SNMPv3 authentication and encryption contribute to a slight increase in the response time when SNMP operations on MIB objects are performed. This cost is far outweighed by the security advantages provided by SNMPv3.
Table 1 shows the order of response time (from least to greatest) for the various security model and security level combinations.
User-Based Security Model
SNMPv3 User-Based Security Model (USM) refers to SNMP message-level security and offers the following services:
- Message integrity—Ensures that messages have not been altered or destroyed in an unauthorized manner and that data sequences have not been altered to an extent greater than can occur nonmaliciously.
- Message origin authentication—Ensures that the claimed identity of the user on whose behalf received data was originated is confirmed.
- Message confidentiality—Ensures that information is not made available or disclosed to unauthorized individuals, entities, or processes.
SNMPv3 authorizes management operations only by configured users and encrypts SNMP messages.
USM uses two authentication protocols:
USM uses Cipher Block Chaining (CBC)-DES (DES-56) as the privacy protocol for message encryption.
View-Based Access Control Model
The View-Based Access Control Model (VACM) enables SNMP users to control access to SNMP managed objects by supplying read, write, or notify access to SNMP objects. It prevents access to objects restricted by views. These access policies can be set when user groups are configured with the snmp-server group command.
MIB Views
For security reasons, it is often valuable to be able to restrict the access rights of some groups to only a subset of the management information within the management domain. To provide this capability, access to a management object is controlled through MIB views, which contain the set of managed object types (and, optionally, the specific instances of object types) that can be viewed.
Access Policy
Access policy determines the access rights of a group. The three types of access rights are as follows:
- read-view access—The set of object instances authorized for the group when objects are read.
- write-view access—The set of object instances authorized for the group when objects are written.
- notify-view access—The set of object instances authorized for the group when objects are sent in a notification.
IP Precedence and DSCP Support for SNMP
SNMP IP Precedence and differentiated services code point (DSCP) support delivers QoS specifically for SNMP traffic. You can change the priority setting so that SNMP traffic generated in a router is assigned a specific QoS class. The IP Precedence or IP DSCP code point value is used to determine how packets are handled in weighted random early detection (WRED).
After the IP Precedence or DSCP is set for the SNMP traffic generated in a router, different QoS classes cannot be assigned to different types of SNMP traffic in that router.
The IP Precedence value is the first three bits in the type of service (ToS) byte of an IP header. The IP DSCP code point value is the first six bits of the differentiate services (DiffServ Field) byte. You can configure up to eight different IP Precedence markings or 64 different IP DSCP markings.
How to Implement SNMP on Cisco IOS XR Software
This section describes how to implement SNMP.
The snmp-server commands enable SNMP on Management Ethernet interfaces by default. For information on how to enable SNMP server support on other inband interfaces, see the Implementing Management Plane Protection on Cisco IOS XR Software module in Cisco IOS XR System Security Configuration Guide for the Cisco XR 12000 Series Router.
- Configuring SNMPv3
- Configuring SNMP Trap Notifications
- Setting the Contact, Location, and Serial Number of the SNMP Agent
- Defining the Maximum SNMP Agent Packet Size
- Changing Notification Operation Values
- Setting IP Precedence and DSCP Values
- Displaying SNMP Context Mapping
- Configuring MIB Data to be Persistent
- Configuring LinkUp and LinkDown Traps for a Subset of Interfaces
Configuring SNMPv3
SUMMARY STEPSThis task explains how to configure SNMPv3 for network management and monitoring.
Note
No specific command enables SNMPv3; the first snmp-server global configuration command that you issue enables SNMPv3. Therefore, the sequence in which you issue the snmp-server commands for this task does not matter.
2. (Optional) snmp-server engineid local engine-id
3. snmp-server view view-name oid-tree {included | excluded}
4. snmp-server group name {v1 | v2c | v3 {auth | noauth | priv}} [read view] [write view] [notify view] [access-list-name]
5. snmp-server user username groupname {v1 | v2c | v3 [auth {md5 | sha} {clear | encrypted} auth-password [priv des56 {clear | encrypted} priv-password]]} [access-list-name]
6. Use one of the following commands:
8. (Optional) show snmp engineid
10. (Optional) show snmp users
DETAILED STEPSConfiguring SNMP Trap Notifications
SUMMARY STEPSThis task explains how to configure the router to send SNMP trap notifications.
Note
You can omit 2 to 4 if you have already completed the steps documented under the Configuring SNMPv3 task.
2. (Optional) snmp-server engineid local engine-id
3. snmp-server group name {v1 | v2c | v3 {auth | noauth | priv}} [read view] [write view] [notify view] [access-list-name]
4. snmp-server user username groupname {v1 | v2c | v3 [auth {md5 | sha} {clear | encrypted} auth-password [priv des56 {clear | encrypted} priv-password]]} [access-list-name]
5. snmp-server host address [traps] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type]
6. snmp-server traps [notification-type]
7. Use one of the following commands:
DETAILED STEPSSetting the Contact, Location, and Serial Number of the SNMP Agent
SUMMARY STEPSThis task explains how to set the system contact string, system location string, and system serial number of the SNMP agent.
Note
The sequence in which you issue the snmp-server commands for this task does not matter.
2. (Optional) snmp-server contact system-contact-string
3. (Optional) snmp-server location system-location
4. (Optional) snmp-server chassis-id serial-number
5. Use one of the following commands:
DETAILED STEPSDefining the Maximum SNMP Agent Packet Size
SUMMARY STEPSThis task shows how to configure the largest SNMP packet size permitted when the SNMP server is receiving a request or generating a reply.
Note
The sequence in which you issue the snmp-server commands for this task does not matter.
2. (Optional) snmp-server packetsize byte-count
3. Use one of the following commands:
DETAILED STEPSChanging Notification Operation Values
SUMMARY STEPSAfter SNMP notifications have been enabled, you can specify a value other than the default for the source interface, message queue length, or retransmission interval.
This task explains how to specify a source interface for trap notifications, the message queue length for each host, and the retransmission interval.
Note
The sequence in which you issue the snmp-server commands for this task does not matter.
2. (Optional) snmp-server trap-source type interface-path-id
3. (Optional) snmp-server queue-length length
4. (Optional) snmp-server trap-timeout seconds
5. Use one of the following commands:
DETAILED STEPSSetting IP Precedence and DSCP Values
SUMMARY STEPS1. configure
2. Use one of the following commands:
3. Use one of the following commands:
DETAILED STEPSDisplaying SNMP Context Mapping
SUMMARY STEPSThe SNMP agent serves queries based on SNMP contexts created by the client features. There is a context mapping table. Each entry in the context mapping table includes a context name, the name of the feature that created the context, and the name of the specific instance of the feature.
DETAILED STEPS
Command or Action Purpose Step 1 show snmp context-mapping
Example:RP/0/0/CPU0:router# show snmp context-mappingDisplays the SNMP context mapping table.
Configuring MIB Data to be Persistent
SUMMARY STEPSMany SNMP MIB definitions define arbitrary 32-bit indices for their object tables. MIB implementations often do a mapping from the MIB indices to some internal data structure that is keyed by some other set of data. In these MIB tables the data contained in the table are often other identifiers of the element being modelled. For example, in the ENTITY-MIB, entries in the entPhysicalTable are indexed by the 31-bit value, entPhysicalIndex, but the entities could also be identified by the entPhysicalName or a combination of the other objects in the table.
Because of the size of some MIB tables, significant processing is required to discover all the mappings from the 32-bit MIB indices to the other data which the network management station identifies the entry. For this reason, it may be necessary for some MIB indices to be persistent across process restarts, switchovers, or device reloads. The ENTITY-MIB entPhysicalTable and CISCO-CLASS-BASED-QOS-MIB are two such MIBs that often require index values to be persistent.
Also, because of query response times and CPU utilization during CISCO-CLASS-BASED-QOS-MIB statistics queries, it is desirable to cache service policy statistics.
1. (Optional) snmp-server entityindex persist
2. (Optional) snmp-server mibs cbqosmib persist
3. (Optional) snmp-server cbqosmib cache refresh time time
4. (Optional) snmp-server cbqosmib cache service-policy count count
5. snmp-server ifindex persist
DETAILED STEPS
Command or Action Purpose Step 1 snmp-server entityindex persist
Example:RP/0/0/CPU0:router(config)# snmp-server entityindex persist(Optional) Enables the persistent storage of ENTITY-MIB data.
Step 2 snmp-server mibs cbqosmib persist
Example:RP/0/0/CPU0:router(config)# snmp-server mibs cbqosmib persist(Optional) Enables persistent storage of the CISCO-CLASS-BASED-QOS-MIB data.
Step 3 snmp-server cbqosmib cache refresh time time
Example:RP/0/0/CPU0:router(config)# snmp-server mibs cbqosmib cache refresh time 45(Optional) Enables QoS MIB caching with a specified cache refresh time.
Step 4 snmp-server cbqosmib cache service-policy count count
Example:RP/0/0/CPU0:router(config)# snmp-server mibs cbqosmib cache service-policy count 50(Optional) Enables QoS MIB caching with a limited number of service policies to cache.
Step 5 snmp-server ifindex persist
Example:RP/0/0/CPU0:router(config)# snmp-server ifindex persistEnables ifIndex persistence globally on all Simple Network Management Protocol (SNMP) interfaces.
Configuring LinkUp and LinkDown Traps for a Subset of Interfaces
SUMMARY STEPSBy specifying a regular expression to represent the interfaces for which you are interested in setting traps, you can enable or disable linkUp and linkDown traps for a large number of interfaces simultaneously.
2. snmp-server interface subset subset-number regular-expression expression
3. notification linkupdown disable
4. Use one of the following commands:
5. (Optional) show snmp interface notification subset subset-number
6. (Optional) show snmp interface notification regular-expression expression
7. (Optional) show snmp interface notification type interface-path-id
DETAILED STEPSConfiguration Examples for Implementing SNMP
Configuring SNMPv3: Examples
Setting an Engine ID
This example shows how to set the identification of the local SNMP engine:
snmp-server engineID local 00:00:00:09:00:00:00:a1:61:6c:20:61
Note
After the engine ID has been configured, the SNMP agent restarts.
Verifying the Identification of the Local SNMP Engines
This example shows how to verify the identification of the local SNMP engine:
config show snmp engineid SNMP engineID 00000009000000a1ffffffffCreating a View
There are two ways to create a view:
- You can include the object identifier (OID) of an ASN.1 subtree of a MIB family from a view by using the included keyword of the snmp-server view command.
- You can exclude the OID subtree of the ASN.1 subtree of a MIB family from a view by using the excluded keyword of the snmp-server view command.
This example shows how to create a view that includes the sysName (1.3.6.1.2.1.1.5) object:
config snmp-server view view_name 1.3.6.1.2.1.1.5 includedThis example shows how to create a view that includes all the OIDs of a system group:
config snmp-server view view_name 1.3.6.1.2.1.1 includedThis example shows how to create a view that includes all the OIDs under the system group except the sysName object (1.3.6.1.2.1.1.5), which has been excluded:
config snmp-server view view_name 1.3.6.1.2.1.1 included snmp-server view view_name 1.3.6.1.2.1.1.5 excludedVerifying Configured Views
This example shows how to display information about the configured views:
RP/0/0/CPU0:router# show snmp view v1default 1.3.6.1 - included nonVolatile active view_name 1.3.6.1.2.1.1 - included nonVolatile active view_name 1.3.6.1.2.1.1.5 - excluded nonVolatile activeCreating Groups
If you do not explicitly specify a notify, read, or write view, the Cisco IOS XR software uses the v1 default (1.3.6.1). This example shows how to create a group that utilizes the default view:
RP/0/0/CPU0:router(config)# snmp-server group group-name v3 authThe following configuration example shows how to create a group that has read access to all the OIDs in the system except the sysUpTime object (1.3.6.1.2.1.1.3), which has been excluded from the view applied to the group, but write access only to the sysName object (1.3.6.1.2.1.1.5):
! snmp-server view view_name1 1.3.6.1.2.1.1 included snmp-server view view_name1 1.3.6.1.2.1.1.3 excluded snmp-server view view_name2 1.3.6.1.2.1.1.5 included snmp-server group group_name v3 auth read view_name1 write view_name2 !Verifying Groups
This example shows how to verify the attributes of configured groups:
RP/0/0/CPU0:router# show snmp group groupname: group_name security model:usm readview : view_name1 writeview: view_name2 notifyview: v1default row status: nonVolatileCreating and Verifying Users
Given the following SNMPv3 view and SNMPv3 group configuration:
! snmp-server view view_name1 1.3.6.1.2.1.1 included snmp-server group group_name v3 noauth read view_name write view-name !This example shows how to create a noAuthNoPriv user with read and write view access to a system group:
config snmp-server user noauthuser group_name v3
Note
The user must belong to a noauth group before a noAuthNoPriv user can be created.
This example shows how to verify the attributes that apply to the SNMP user:
RP/0/0/CPU0:router# show snmp user User name: noauthuser Engine ID: localSnmpID storage-type: nonvolatile activeGiven the following SNMPv3 view and SNMPv3 group configuration:
! snmp-server view view_name 1.3.6.1.2.1.1 included snmp group group_name v3 priv read view_name write view_name !This example shows how to create authNoPriv user with read and write view access to a system group:
RP/0/0/CPU0:router(config)# snmp-server user authuser group_name v3 auth md5 clear auth_passwd
Note
Because the group is configured at a security level of Auth, the user must be configured as “auth” at a minimum to access this group (“priv” users could also access this group). The authNoPriv user configured in this group, authuser, must supply an authentication password to access the view. In the example, auth_passwd is set as the authentication password string. Note that clear keyword is specified before the auth_passwd password string. The clear keyword indicates that the password string being supplied is unencrypted.
This example shows how to verify the attributes that apply to SNMP user:
RP/0/0/CPU0:router# show snmp user User name: authuser Engine ID: localSnmpID storage-type: nonvolatile activeGiven the following SNMPv3 view and SNMPv3 group configuration:
! snmp view view_name 1.3.6.1.2.1.1 included snmp group group_name v3 priv read view_name write view_name !This example shows how to create an authPriv user with read and write view access to a system group:
config snmp-server user privuser group_name v3 auth md5 clear auth_passwd priv des56 clear priv_passwd
Note
Because the group has a security level of Priv, the user must be configured as a “priv” user to access this group. In this example, the user, privuser, must supply both an authentication password and privacy password to access the OIDs in the view.
This example shows how to verify the attributes that apply to the SNMP user:
RP/0/0/CPU0:router# show snmp user User name: privuser Engine ID: localSnmpID storage-type: nonvolatile activeConfiguring Trap Notifications: Example
The following example configures an SNMP agent to send out different types of traps. The configuration includes a v2c user, a noAuthNoPriv user, anauthNoPriv user, and an AuthPriv user.
Note
The default User Datagram Protocol (UDP) port is 161. If you do not a specify a UDP port with the udp-port keyword and port argument, then the configured SNMP trap notifications are sent to port 161.
! snmp-server host 10.50.32.170 version 2c userv2c udp-port 2345 snmp-server host 10.50.32.170 version 3 auth userV3auth udp-port 2345 snmp-server host 10.50.32.170 version 3 priv userV3priv udp-port 2345 snmp-server host 10.50.32.170 version 3 noauth userV3noauth udp-port 2345 snmp-server user userv2c groupv2c v2c snmp-server user userV3auth groupV3auth v3 auth md5 encrypted 140F0A13 snmp-server user userV3priv groupV3priv v3 auth md5 encrypted 021E1C43 priv des56 encrypted 1110001C snmp-server user userV3noauth groupV3noauth v3 LROwner snmp-server view view_name 1.3 included snmp-server community public RW snmp-server group groupv2c v2c read view_name snmp-server group groupV3auth v3 auth read view_name snmp-server group groupV3priv v3 priv read view_name snmp-server group groupV3noauth v3 noauth read view_name !This example shows how to verify the configuration SNMP trap notification recipients host, the recipients of SNMP trap notifications. The output displays the following information:
- IP address of the configured notification host
- UDP port where SNMP notification messages are sent
- Type of trap configured
- Security level of the configured user
- Security model configured
config show snmp host Notification host: 10.50.32.170 udp-port: 2345 type: trap user: userV3auth security model: v3 auth Notification host: 10.50.32.170 udp-port: 2345 type: trap user: userV3noauth security model: v3 noauth Notification host: 10.50.32.170 udp-port: 2345 type: trap user: userV3priv security model: v3 priv Notification host: 10.50.32.170 udp-port: 2345 type: trap user: userv2c security model: v2cAdditional References
Related Documents
Related Topic
Document Title
Cisco IOS XR SNMP commands
SNMP Server Commands on the Cisco IOS XR Software module of Cisco IOS XR System Management Command Reference for the Cisco XR 12000 Series Router
Cisco IOS XR commands
Cisco IOS XR Commands Master List for the Cisco XR 12000 Series Router
Getting started with Cisco IOS XR software
Cisco IOS XR Getting Started Guide for the Cisco XR 12000 Series Router
Information about user groups and task IDs
Configuring AAA Services on the Cisco IOS XR Software module of Cisco IOS XR System Security Configuration Guide for the Cisco XR 12000 Series Router
Cisco IOS XR Quality of Service
Cisco IOS XR Modular Quality of Service Configuration Guide for the Cisco XR 12000 Series Router
MIBs
MIBs
MIBs Link
— To locate and download MIBs using Cisco IOS XR software, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http://cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml
RFCs
RFCs
Title
RFC 3411
An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks
RFC 3412
Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)
RFC 3413
Simple Network Management Protocol (SNMP) Applications
RFC 3414
User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)
RFC 3415
View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)
RFC 3416
Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP)
RFC 3417
Transport Mappings for the Simple Network Management Protocol (SNMP)
RFC 3418
Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)
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