Table of Contents

no snmp-server
show snmp
show snmp engineID
show snmp group
show snmp pending
show snmp sessions
show snmp user
snmp-server access-policy
snmp-server chassis-id
snmp-server community
snmp-server contact
snmp-server context
snmp-server enable informs
snmp-server enable traps
snmp-server engineID
snmp-server group
snmp-server host
snmp-server informs
snmp-server location
snmp-server manager
snmp-server manager session-timeout
snmp-server packetsize
snmp-server queue-length
snmp-server system-shutdown
snmp-server tftp-server-list
snmp-server trap-authentication
snmp-server trap-source
snmp-server trap-timeout
snmp-server user
snmp-server view
snmp trap link-status

SNMP Commands

This chapter describes commands used to configure Simple Network Management Protocol (SNMP) on your routers for the purposes of network monitoring and management.

For SNMP configuration tasks and examples, refer to the "Configuring SNMP Support" chapter in the Release 12.1 Cisco IOS Configuration Fundamentals Configuration Guide.

no snmp-server

To disable Simple Network Management Protocol agent operation, use the no snmp-server command.

Syntax Description

This command has no arguments or keywords.

Defaults

None

Command Modes

EXEC

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command disables all running versions of SNMP (SNMPv1, SNMPv2C, SNMPv3) on the server.

Examples

The following example disables the current running version of SNMP:

no snmp-server

show snmp

To check the status of SNMP communications, use the show snmp EXEC command.

This command provides counter information for SNMP operations. It also displays the chassis ID string defined with the snmp-server chassis-id command.

Examples

The following is sample output from the show snmp command:

Router# show snmp
 
Chassis: 01506199
37 SNMP packets input
    0 Bad SNMP version errors
    4 Unknown community name
    0 Illegal operation for community name supplied
    0 Encoding errors
    24 Number of requested variables
    0 Number of altered variables
    0 Get-request PDUs
    28 Get-next PDUs
    0 Set-request PDUs
78 SNMP packets output
    0 Too big errors (Maximum packet size 1500)
    0 No such name errors
    0 Bad values errors
    0 General errors
    24 Response PDUs
    13 Trap PDUs
 
SNMP logging: enabled
    Logging to 171.69.58.33.162, 0/10, 13 sent, 0 dropped.
 
SNMP Manager-role output packets
    4 Get-request PDUs
    4 Get-next PDUs
    6 Get-bulk PDUs
    4 Set-request PDUs
    23 Inform-request PDUs
    30 Timeouts
    0 Drops
SNMP Manager-role input packets
    0 Inform response PDUs
    2 Trap PDUs
    7 Response PDUs
    1 Responses with errors
 
SNMP informs: enabled
    Informs in flight 0/25 (current/max)
    Logging to 171.69.217.141.162
        4 sent, 0 in-flight, 1 retries, 0 failed, 0 dropped
    Logging to 171.69.58.33.162
        0 sent, 0 in-flight, 0 retries, 0 failed, 0 dropped
 

Table 39 describes the fields shown in the display.

Table 39: show snmp Field Descriptions

Field	Description
Chassis	Chassis ID string.
SNMP packets input	Total number of SNMP packets input.
Bad SNMP version errors	Number of packets with an invalid SNMP version.
Unknown community name	Number of SNMP packets with an unknown community name.
Illegal operation for community   name supplied	Number of packets requesting an operation not allowed for that community.
Encoding errors	Number of SNMP packets that were improperly encoded.
Number of requested variables	Number of variables requested by SNMP managers.
Number of altered variables	Number of variables altered by SNMP managers.
Get-request PDUs	Number of get requests received.
Get-next PDUs	Number of get-next requests received.
Set-request PDUs	Number of set requests received.
SNMP packets output	Total number of SNMP packets sent by the router.
Too big errors	Number of SNMP packets which were larger than the maximum packet size.
Maximum packet size	Maximum size of SNMP packets.
No such name errors	Number of SNMP requests that specified an MIB object which does not exist.
Bad values errors	Number of SNMP set requests that specified an invalid value for an MIB object.
General errors	Number of SNMP set requests that failed due to some other error. (It was not a noSuchName error, badValue error, or any of the other specific errors.)
Response PDUs	Number of responses sent in reply to requests.
Trap PDUs	Number of SNMP traps sent
SNMP logging	Indicates whether logging is enabled or disabled.
sent	Number of traps sent.
dropped	Number of traps dropped. Traps are dropped when the trap queue for a destination exceeds the maximum length of the queue, as set by the snmp-server queue-length command.
SNMP Manager-role output packets	Information related to packets sent by the router as an SNMP manager.
Get-request PDUs	Number of get requests sent.
Get-next PDUs	Number of get-next requests sent.
Get-bulk PDUs	Number of get-bulk requests sent.
Set-request PDUs	Number of set requests sent.
Inform-request PDUs	Number of inform requests sent.
Timeouts	Number of request timeouts.
Drops	Number of requests dropped. Reasons for drops include no memory, a bad destination address, or an unreasonable destination address.
SNMP Manager-role input packets	Information related to packets received by the router as an SNMP manager.
Inform response PDUs	Number of inform request responses received.
Trap PDUs	Number of SNMP traps received.
Response PDUs	Number of responses received.
Responses with errors	Number of responses containing errors.
SNMP informs	Indicates whether SNMP informs are enabled.
Informs in flight	Current and maximum possible number of informs waiting to be acknowledged.
Logging to	Destination of the following informs.
sent	Number of informs sent to this host.
in-flight	Number of informs currently waiting to be acknowledged.
retries	Number of inform retries sent.
failed	Number of informs that were never acknowledged.
dropped	Number of unacknowledged informs that were discarded to make room for new informs.

show snmp engineID

To display the identification of the local Simple Network Management Protocol engine and all remote engines that have been configured on the router, use the show snmp engineID EXEC command.

Syntax Description

This command has no arguments or keywords.

Command Modes

EXEC

Command History

Release	Modification
12.0(3)T	This command was introduced.

Usage Guidelines

An SNMP engine is a copy of SNMP that can reside on a local or remote device.

Examples

The following example specifies 00000009020000000C025808 as the local engineID and 123456789ABCDEF000000000 as the remote engine ID, 171.69.37.61 as the IP address of the remote engine, or copy of SNMP, and 162 as the port from which the remote device is connected to the local device:

router# show snmp engineID
 
Local SNMP engineID: 00000009020000000C025808
Remote Engine ID	IP-addr				Port
123456789ABCDEF000000000	171.69.37.61		162
 

Table 1 describes the fields shown in the example.
Table 40: show snmp engineID Field Descriptions

Field	Definition
Local SNMP engine ID	A string that identifies the copy of SNMP on the local device.
Remote Engine ID	A string that identifies the copy of SNMP on the remote device.
IP-addr	The IP address of the remote device.
Port	The port number on the local device to which the remote device is connected.

Related Commands

Command	Description
snmp-server engineID	Configures a name for either the local or remote SNMP engine on the router.

show snmp group

To display the names of groups on the router and the security model, the status of the different views, and the storage type of each group, use the show snmp group EXEC command.

Syntax Description

This command has no keywords or arguments.

Command Modes

EXEC

Command History

Release	Modification
12.0(3)T	This command was introduced.

Examples

The following example specifies the group name as public, the security model as v1, the read view name as v1default, the notify view name as *tv.FFFFFFFF, and the storage type as volatile:

router# show snmp group
 
groupname: public		security model:v1
readview:v1default
writeview:  no writeview specified 
notifyview: *tv.FFFFFFFF
storage-type: volatile
 

Table 41 describes the fields shown in the example.
Table 41: show snmp group Field Descriptions

Field	Definition
groupname	The name of the SNMP group, or collection of users who have a common access policy.
security model	The security model used by the group, either v1, v2c, or v3.
readview	A string identifying the read view of the group.
writeview	A string identifying the write view of the group.
notifyview	A string identifying the notify view of the group.
storage-type	Indicates whether the settings have been set in volatile or temporary memory on the device, or in non-volatile or persistent memory where settings will remain after the device has been turned off and on again.

show snmp pending

To display the current set of pending Simple Network Management Protocol requests, use the show snmp pending EXEC command.

Router# show snmp pending
 
req id: 47, dest: 171.69.58.33.161, V2C community: public, Expires in 5 secs
req id: 49, dest: 171.69.58.33.161, V2C community: public, Expires in 6 secs
req id: 51, dest: 171.69.58.33.161, V2C community: public, Expires in 6 secs
req id: 53, dest: 171.69.58.33.161, V2C community: public, Expires in 8 secs
 

Table 42 describes the fields shown in the display.

Table 42: show snmp pending Field Descriptions

Field	Description
req id	ID number of the pending request.
dest	IP address of the intended receiver of the request.
V2C Community	SNMP version 2C community string sent with the request.
Expires in	Remaining time before request timeout expires.

show snmp sessions

To display the current SNMP sessions, use the show snmp sessions EXEC command.

Router# show snmp sessions
 
Destination: 171.69.58.33.162, V2C community: public
  Round-trip-times: 0/0/0 (min/max/last)
  packets output
    0 Gets, 0 GetNexts, 0 GetBulks, 0 Sets, 4 Informs
    0 Timeouts, 0 Drops
  packets input
    0 Traps, 0 Informs, 0 Responses (0 errors)
Destination: 171.69.217.141.162, V2C community: public, Expires in 575 secs
  Round-trip-times: 1/1/1 (min/max/last)
  packets output
    0 Gets, 0 GetNexts, 0 GetBulks, 0 Sets, 4 Informs
    0 Timeouts, 0 Drops
  packets input
    0 Traps, 0 Informs, 4 Responses (0 errors)
 

Router# show snmp sessions brief
 
Destination: 171.69.58.33.161, V2C community: public, Expires in 55 secs
 

Table 43 describes the fields shown in these displays.

Table 43: show snmp sessions Field Descriptions

Field	Description
Destination	IP address of the remote agent.
V2C community	SNMP version 2C community string used to communicate with the remote agent.
Expires in	Remaining time before the session timeout expires.
Round-trip-times	Minimum, maximum, and the last round-trip time to the agent.
packets output	Packets sent by the router.
Gets	Number of get requests sent.
GetNexts	Number of get-next requests sent.
GetBulks	Number of get-bulk requests sent.
Sets	Number of set requests sent.
Informs	Number of inform requests sent.
Timeouts	Number of request timeouts.
Drops	Number of packets that could not be sent.
packets input	Packets received by the router.
Traps	Number of traps received.
Informs	Number of inform responses received.
Responses	Number of request responses received.
errors	Number of responses that contained an SNMP error code.

show snmp user

To display information on each Simple Network Management Protocol username in the group username table, use the show snmp user EXEC command.

Syntax Description

This command has no arguments or keywords.

Command Modes

EXEC

Command History

Release	Modification
12.0(3)T	This command was introduced.

Usage Guidelines

An SNMP user is a remote user for which an SNMP management operation is performed. For example, inform operations can be sent to a user on a remote SNMP engine. The user is designated using the snmp-server user command.

Examples

The following example specifies the username as authuser, the engine ID string as 00000009020000000C025808, and the storage-type as nonvolatile:

router# show snmp user
 
User name: authuser
Engine ID: 00000009020000000C025808
storage-type: nonvolatile
 

Table 44 describes fields shown in the example.
Table 44: show snmp user Field Descriptions

Field	Definition
User name	A string identifying the name of the SNMP user.
Engine ID	A string identifying the name of the copy of SNMP on the device.
storage-type	Indicates whether the settings have been set in volatile or temporary memory on the device, or in nonvolatile or persistent memory where settings will remain after the device has been turned off and on again.

snmp-server access-policy

This command is no longer valid. The functionality provided by this command has been removed from the Cisco IOS software.

snmp-server chassis-id

To provide a message line identifying the Simple Network Management Protocol server serial number, use the snmp-server chassis-id global configuration command. Use the no form of this command to restore the default value, if any.

The chassis ID message can be seen with the show snmp command.

Examples

In the following example, the chassis serial number specified is 1234456:

snmp-server chassis-id 1234456

Related Commands

Command	Description
show snmp	Checks the status of SNMP communications.

snmp-server community

To set up the community access string to permit access to the Simple Network Management Protocol protocol, use the snmp-server community global configuration command. The no form of this command removes the specified community string.

string [view view-name] [ro | rw] [number]

no snmp-server community string

Syntax Description

string	Community string that acts like a password and permits access to the SNMP protocol.
view view-name	(Optional) Name of a previously defined view. The view defines the objects available to the community.
ro	(Optional) Specifies read-only access. Authorized management stations are only able to retrieve MIB objects.
rw	(Optional) Specifies read-write access. Authorized management stations are able to both retrieve and modify MIB objects.
number	(Optional) Integer from 1 to 99 that specifies an access list of IP addresses that are allowed to use the community string to gain access to the SNMP agent.

Defaults

By default, an SNMP community string permits read-only access to all objects.

---

Note   If the snmp-server community command is not used during the SNMP configuration session, it will automatically be added to the configuration after the snmp host command is used. In this case, the default password (string) for the snmp-server community will be taken from the snmp host command.

---

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

The no snmp-server command disables all versions of SNMP (SNMPv1, SNMPv2C, SNMPv3).

The first snmp-server command that you enter enables all versions of SNMP.

Examples

The following example assigns the string comaccess to SNMP allowing read-only access and specifies that IP access list 4 can use the community string:

snmp-server community comaccess ro 4
 

The following example assigns the string mgr to SNMP allowing read-write access to the objects in the restricted view:

snmp-server community mgr view restricted rw
 

The following example removes the community comaccess:

no snmp-server community comaccess
 

The following example disables all versions of SNMP:

no snmp-server 

Related Commands

Command	Description
access-list	Configures the access list mechanism for filtering frames by protocol type or vendor code.
snmp-server view	Creates or updates a view entry.

snmp-server contact

To set the system contact (sysContact) string, use the snmp-server contact global configuration command. Use the no form to remove the system contact information.

snmp-server contact Dial System Operator at beeper # 27345

snmp-server context

This command is no longer valid. The functionality provided by this command has been removed from the Cisco IOS software.

snmp-server enable informs

To enable the router to send Simple Network Management Protocol informs, use the snmp-server enable infroms global configuration command. Use the no form of this command to disable SNMP inform notifications.

Syntax Description

This command has no arguments or keywords.

Defaults

This command is disabled by default. Most notification types are disabled. However, some notification types cannot be controlled with this command. For example, some notification types are always enabled. Other notification types are enabled by a different command. For example, the linkUpDown notifications are controlled by the snmp trap link-status command.

Command History

Release	Modification
11.1	This command was introduced.

Command Modes

Global configuration

Usage Guidelines

SNMP notifications can be sent as traps or inform requests. This command enables only inform requests for the specified notification types. To enable SNMP traps, use the snmp-server enable traps command.

The snmp-server enable informs command is used in conjunction with the snmp-server host command. Use the snmp-server host command to specify which host or hosts receive SNMP notifications. In order to send notifications, you must configure at least one snmp-server host command.

The notification types used in this command all have an associated MIB object that allows them to be globally enabled or disabled. Not all of the notification types available in the snmp-server host command have notificationEnable MIB objects, so some of these cannot be controlled using the snmp-server enable commands.

Examples

The following example enables the router to send all informs to the host specified by the name myhost.cisco.com, using the community string defined as public:

snmp-server enable informs
snmp-server host myhost.cisco.com public
 

Related Commands

Command	Description
snmp-server enable traps	Enables or disables the sending of SNMP trap notifications from the router.
snmp-server host	Specifies the recipient of an SNMP notification operation.
snmp-server informs	Configures specific characteristics for SNMP inform requests.
snmp-server trap-source	Specifies the interface (and hence the corresponding IP address) that an SNMP trap should originate from.
snmp trap illegal-address	Issues an SNMP trap when a MAC address violation is detected on an Ethernet hub port of a Cisco 2505, Cisco 2507, or Cisco 2516 router.

snmp-server enable traps

To enable the router to send Simple Network Management Protocol traps, use the snmp-server enable traps global configuration command. Use the no form of this command to disable SNMP notifications.

Syntax Description

notification-type

(Optional) Type of notification to enable. If no type is specified, all notifications are sent (including the envmon and repeater notifications). The notification type can be one of the following keywords: bgp--Sends Border Gateway Protocol (BGP) state change notifications. config--Sends configuration notifications. entity--Sends Entity MIB modification notifications. envmon--Sends Cisco enterprise-specific environmental monitor notifications when an environmental threshold is exceeded. When the envmon keyword is used, you can specify a notification-option value. frame-relay--Sends Frame Relay notifications. hsrp--Sends Hot Standby Routing Protocol (HSRP) notifications. isdn--Sends Integrated Services Digital Network (ISDN) notifications. When the isdn keyword is used, you can specify a notification-option value. repeater--Sends Ethernet hub repeater notifications. When the repeater keyword is selected, you can specify a notification-option value. rsvp--Sends Resource Reservation Protocol (RSVP) notifications. rtr--Sends Service Assurance Agent RTR (RTR) notifications. snmp--Sends Simple Network Management Protocol (SNMP) notifications. When the snmp keyword is used, you can specify a notification-option value. syslog--Sends error message notifications (Cisco Syslog MIB). Specify the level of messages to be sent with the logging history level command.

notification-option

(Optional) envmon [voltage | shutdown | supply | fan | temperature] --When the envmon keyword is used, you can enable a specific environmental notification type, or accept all notification types from the environmental monitor system. If no option is specified, all environmental notifications are enabled. The option can be one or more of the following keywords: voltage, shutdown, supply, fan, and temperature. isdn [call-information | isdn u-interface] --When the isdn keyword is used, you can specify the call-information keyword to enable an SNMP ISDN call information notification for the ISDN MIB subsystem, or you can specify the isdnu-interface keyword to enable an SNMP ISDN U interface notification for the ISDN U interface MIB subsystem. repeater [health | reset] --When the repeater keyword is used, you can specify the repeater option. If no option is specified, all repeater notifications are enabled. The option can be one or more of the following keywords: health--Enables IETF Repeater Hub MIB (RFC 1516) health notification. reset--Enables IETF Repeater Hub MIB (RFC 1516) reset notification. snmp [authentication] --When the snmp keyword is used, you can specify the authentication option to enable SNMP Authentication Failure notifications. (The snmp-sever enable traps snmp authentication command replaces the snmp-server trap-authentication command.) If no option is specified, all SNMP notifications are enabled

Defaults

This command is disabled by default. Most notification types are disabled. However, some notification types cannot be controlled with this command. For example, some notification types are always enabled. Other notification types are enabled by a different command. For example, the linkUpDown notifications are controlled by the snmp trap link-status command.

If you enter this command with no notification-type keywords, the default is to enable all notification types controlled by this command.

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.
12.0(2)T	The rsvp keyword was added.
12.0(3)T	The hsrp keyword was added.

Usage Guidelines

This command is useful for disabling notifications that are generating a large amount of uninteresting or useless noise.

SNMP notifications can be sent as traps or inform requests. This command enables both traps and inform requests for the specified notification types.

If you do not enter an snmp-server enable traps command, no notifications controlled by this command are sent. In order to configure the router to send these SNMP notifications, you must enter at least one snmp-server enable traps command. If you enter the command with no keywords, all notification types are enabled. If you enter the command with a keyword, only the notification type related to that keyword is enabled. In order to enable multiple types of notifications, you must issue a separate snmp-server enable traps command for each notification type and notification option.

The snmp-server enable traps command is used in conjunction with the snmp-server host command. Use the snmp-server host command to specify which host or hosts receive SNMP notifications. In order to send notifications, you must configure at least one snmp-server host command.

For a host to receive a notification controlled by this command, both the snmp-server enable traps command and the snmp-server host command for that host must be enabled. If the notification type is not controlled by this command, just the appropriate snmp-server host command must be enabled.

The notification types used in this command all have an associated MIB object that allows them to be globally enabled or disabled. Not all of the notification types available in the snmp-server host command have notificationEnable MIB objects, so some of these cannot be controlled using the snmp-server enable command.

Examples

The following example enables the router to send all traps to the host specified by the name myhost.cisco.com, using the community string defined as public:

snmp-server enable traps
snmp-server host myhost.cisco.com public
 

The following example enables the router to send Frame Relay and environmental monitor traps to the host myhost.cisco.com using the community string public:

snmp-server enable traps frame-relay
snmp-server enable traps envmon temperature
snmp-server host myhost.cisco.com public
 

The following example will not send traps to any host. The BGP traps are enabled for all hosts, but the only traps enabled to be sent to a host are ISDN traps (which are not enabled in this example).

snmp-server enable traps bgp
snmp-server host bob public isdn
 

The following example enables the router to send all inform requests to the host labeled myhost.cisco.com using the community string defined as public:

snmp-server enable traps
snmp-server host myhost.cisco.com informs version 2c public
 

The following example sends HSRP MIB traps to the host myhost.cisco.com using the community string public.

snmp-server enable hsrp
snmp-server host myhost.cisco.com traps version 2c public hsrp
 

Related Commands

Command	Description
snmp-server enable informs
snmp-server host	Specifies the recipient of an SNMP notification operation.
snmp-server informs	Specifies inform request options.
snmp-server trap-source	Specifies the interface (and hence the corresponding IP address) that an SNMP trap should originate from.
snmp trap illegal-address	Issues an SNMP trap when a MAC address violation is detected on an Ethernet hub port of a Cisco 2505, Cisco 2507, or Cisco 2516 router.

snmp-server engineID

To configure a name for either the local or remote Simple Network Management Protocol engine on the router, use the snmp-server engineID global configuration command. Use the no form of this command to remove a specified SNMP group.

Syntax Description

local	(Optional) Specifies the local copy of SNMP on the router.
engineid-string	(Optional) The name of a copy of SNMP.
remote	(Optional) Specifies the remote copy of SNMP on the router.
ip-address	(Optional) The IP address of the device that contains the remote copy of SNMP.
udp-port	(Optional) Specifies a UDP port of the host to use.
port	(Optional) The socket number on the remote device that contains the remote copy of SNMP. The default is 161.

Defaults

No default behavior or values.

Command Modes

Global configuration

Command History

Release	Modification
12.0(3)T	This command was introduced.

Usage Guidelines

Note that you need not specify the entire 24-character engine ID if it contains trailing zeros. Specify only the portion of the Engine ID up until the point where only zeros remain in the value. To configure an engine ID of 123400000000000000000000, you can specify the value 1234, for example, snmp-server engineID local 1234.

Changing the value of snmpEngineID has important side-effects. A user's password (entered on the command line) is converted to an MD5 or SHA security digest. This digest is based on both the password and the local engine ID. The command line password is then destroyed, as required by RFC 2274. Because of this deletion, if the local value of engineID changes, the security digests of SNMPv3 users will be invalid, and the users will have to be reconfigured.

Similar restrictions require the reconfiguration of community strings when the engine ID changes. A remote engine ID is required when an SNMPv3 inform is configured. The remote engine ID is used to compute the security digest for authenticating and encrypting packets sent to a user on the remote host. Please refer to the examples in the Configuring Informs section in the snmp-server host command reference page.

Related Commands

Command	Description
show snmp engineID	Displays the identification of the local SNMP engine and all remote engines that have been configured on the router.
snmp-server host	Specifies the recipient (SNMP manager) of an SNMP trap notification.

snmp-server group

To configure a new Simple Network Management Protocol group, or a table that maps SNMP users to SNMP views, use the snmp-server group global configuration command. To remove a specified SNMP group, use the no form of this command.

Syntax Description

groupname	(Optional) The name of the group.
v1	(Optional) The least secure of the possible security models.
v2c	(Optional) The second least secure of the possible security models. It allows for the transmission of informs and counter 64, which allows for integers twice the width of what is normally allowed.
v3	(Optional) The most secure of the possible security models.
auth	(Optional) Specifies authentication of a packet without encrypting it.
noauth	(Optional) Specifies no authentication of a packet.
priv	(Optional) Specifies authentication of a packet with encryption.
read	(Optional) The option that allows you to specify a read view.
readview	(Optional) A string (not to exceed 64 characters) that is the name of the view that enables you only to view the contents of the agent.
write	(Optional) The option that allows you to specify a write view.
writeview	(Optional) A string (not to exceed 64 characters) that is the name of the view that enables you to enter data and configure the contents of the agent.
notify	(Optional) The option that allows you to specify a notify view
notifyview	(Optional) A string (not to exceed 64 characters) that is the name of the view that enables you to specify a notify, inform, or trap.
access	(Optional) The option that enables you to specify an access list.
access-list	(Optional) A string (not to exceed 64 characters) that is the name of the access list.

Defaults

Table 45 describes default values for the different views.
Table 45: snmp server group Default Descriptions

Default	Definition
readview	Assumed to be every object belonging to the Internet (1.3.6.1) OID space, unless the user uses the read option to override this state.
writeview	Nothing is defined for the write view (that is, the null OID). You must configure write access.
notifyview	Nothing is defined for the notify view (that is, the null OID). If a view is specified, any notifications in that view that are generated will be sent to all users associated with the group (provided an SNMP server host configuration exists for the user).

snmp-server user John Johngroup v3 auth md5 arizona2.
 

snmp-server user John Johngroup v3 encrypted auth md5 00:11:22:33:44:55:66:77:88:99:AA:BB:CC:DD:EE:FF
 

snmp-server host

To specify the recipient of an Simple Network Management Protocol notification operation, use the snmp-server host global configuration command. To remove the specified host, use the no form of this command.

Syntax Description

host-addr	Name or Internet address of the host (the targeted recipient).
traps	(Optional) Send SNMP traps to this host. This is the default.
informs	(Optional) Send SNMP informs to this host.
version	(Optional) Version of the Simple Network Management Protocol (SNMP) used to send the traps. Version 3 is the most secure model, as it allows packet encryption with the priv keyword. If you use the version keyword, one of the following must be specified: 1 --SNMPv1. This option is not available with informs. 2c --SNMPv2C. 3 --SNMPv3. The following three optional keywords can follow the version 3 keyword: auth (Optional). Enables Message Digest 5 (MD5) and Secure Hash Algorithm (SHA) packet authentication noauth (Default). The noAuthNoPriv security level. This is the default if the [auth | noauth | priv] keyword choice is not specified. priv (Optional). Enables Data Encryption Standard (DES) packet encryption (also called "privacy").
community-string	Password-like community string sent with the notification operation. Though you can set this string using the snmp-server host command by itself, we recommend you define this string using the snmp-server community command prior to using the snmp-server host command.
udp-port port	UDP port of the host to use. The default is 162.
notification-type	(Optional) Type of notification to be sent to the host. If no type is specified, all notifications are sent. The notification type can be one or more of the following keywords: bgp--Sends Border Gateway Protocol (BGP) state change notifications. config--Sends configuration notifications. dspu--Sends downstream physical unit (DSPU) notifications. entity--Sends Entity MIB modification notifications. envmon--Sends Cisco enterprise-specific environmental monitor notifications when an environmental threshold is exceeded. frame-relay--Sends Frame Relay notifications. hsrp--Sends Hot Standby Routing Protocol (HSRP) notifications. isdn--Sends Integrated Services Digital Network (ISDN) notifications. llc2--Sends Logical Link Control, type 2 (LLC2) notifications. repeater--Sends standard repeater (hub) notifications. rsrb--Sends remote source-route bridging (RSRB) notifications. rsvp--Sends Resource Reservation Protocol (RSVP) notifications. rtr--Sends SA Agent (RTR) notifications. sdlc--Sends Synchronous Data Link Control (SDLC) notifications. sdllc--Sends SDLLC notifications. snmp--Sends Simple Network Management Protocol (SNMP) notifications (as defined in RFC 1157). stun--Sends serial tunnel (STUN) notifications. syslog--Sends error message notifications (Cisco Syslog MIB). Specify the level of messages to be sent with the logging history level command. tty--Sends Cisco enterprise-specific notifications when a Transmission Control Protocol (TCP) connection closes. x25--Sends X.25 event notifications.

Defaults

This command is disabled by default. No notifications are sent.

If you enter this command with no keywords, the default is to send all trap types to the host. No informs will be sent to this host.

If no version keyword is present, the default is version 1. The no snmp-server host command with no keywords will disable traps, but not informs, to the host. In order to disable informs, use the no snmp-server host informs command.

Note   If the community-string is not defined using the snmp-server community command prior to using this command, the default form of the snmp-server community command will automatically be inserted into the configuration. The password (community-string) used for this automatic configuration of the snmp-server community will be the same as specified in the snmp-server host command. This is the default behavior for IOS 12.0(3) and later.

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.
12.0(3)T	The following keywords were added:                version 3 [auth | noauth | priv] hsrp

Usage Guidelines

SNMP notifications can be sent as traps or inform requests. Traps are unreliable because the receiver does not send acknowledgments when it receives traps. The sender cannot determine if the traps were received. However, an SNMP entity that receives an inform request acknowledges the message with an SNMP response PDU. If the sender never receives the response, the inform request can be sent again. Thus, informs are more likely to reach their intended destination.

However, informs consume more resources in the agent 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, while an inform may be retried several times. The retries increase traffic and contribute to a higher overhead on the network.

If you do not enter an snmp-server host command, no notifications are sent. In order to configure the router to send SNMP notifications, you must enter at least one snmp-server host command. If you enter the command with no keywords, all trap types are enabled for the host.

In order to enable multiple hosts, you must issue a separate snmp-server host command for each host. You can specify multiple notification types in the command for each host.

When multiple snmp-server host commands are given for the same host and kind of notification (trap or inform), each succeeding command overwrites the previous command. Only the last snmp-server host command will be in effect. For example, if you enter an snmp-server host inform command for a host and then enter another snmp-server host inform command for the same host, the second command will replace the first.

The snmp-server host command is used in conjunction with the snmp-server enable command. Use the snmp-server enable command to specify which SNMP notifications are sent globally. For a host to receive most notifications, at least one snmp-server enable command and the snmp-server host command for that host must be enabled.

However, some notification types cannot be controlled with the snmp-server enable command. For example, some notification types are always enabled. Other notification types are enabled by a different command. For example, the linkUpDown notifications are controlled by the snmp trap link-status command. These notification types do not require an snmp-server enable command.

A notification-type option's availability depends on the router type and Cisco IOS software features supported on the router. For example, the envmon notification-type is available only if the environmental monitor is part of the system.

Configuring Informs

To be able to send an inform, you need to perform the following steps:

	Task
Step 1	Configure a remote engine ID.
Step 2	Configure a remote user.
Step 3	Configure a group on a remote device.
Step 4	Enable traps on the remote device.
Step 5	Enable the SNMP manager.

Examples

If you want to configure a unique snmp community string for traps, but you want to prevent snmp polling access with this string, the configuration should include an access-list. In the following example, the community string is named "comaccess" and the access list is numbered 10:

snmp-server community comaccess ro 10
snmp-server host 172.20.2.160 comaccess
access-list 10 deny any
 

The following example sends the SNMP traps to the host specified by the name myhost.cisco.com. The community string is defined as comaccess.

snmp-server enable traps
snmp-server host myhost.cisco.com comaccess snmp
 

The following example sends the SNMP and Cisco environmental monitor enterprise-specific traps to address 172.30.2.160:

snmp-server enable traps
snmp-server host 172.30.2.160 public snmp envmon
 

The following example enables the router to send all traps to the host myhost.cisco.com using the community string public:

snmp-server enable traps
snmp-server host myhost.cisco.com public
 

The following example will not send traps to any host. The BGP traps are enabled for all hosts, but only the ISDN traps are enabled to be sent to a host.

snmp-server enable traps bgp
snmp-server host bob public isdn
 

The following example enables the router to send all inform requests to the host myhost.cisco.com using the community string public:

snmp-server enable traps
snmp-server host myhost.cisco.com informs version 2c public
 

The following example sends HSRP MIB traps to the host specified by the name myhost.cisco.com. The community string is defined as public.

snmp-server enable hsrp
snmp-server host myhost.cisco.com traps version 2c public hsrp
 

Related Commands

Command	Description
snmp-server host	Specifies the recipient of an SNMP notification operation.
snmp-server informs	Specifies inform request options.
snmp-server trap-source	Specifies the interface (and hence the corresponding IP address) that an SNMP trap should originate from.
snmp-server trap-timeout	Defines how often to try resending trap messages on the retransmission queue.

snmp-server informs

To specify inform request options, use the snmp-server informs global configuration command. The no form of this command returns the settings to the defaults.

snmp-server informs pending 50
 

snmp-server informs timeout 60 pending 40
 

snmp-server informs timeout 5
 

snmp-server informs retries 10 pending 45

snmp-server location

To set the system location string, use the snmp-server location global configuration command. Use the no form of this command to remove the location string.

snmp-server location Building 3/Room 214

snmp-server manager

To start the Simple Network Management Protocol manager process, use the snmp-server manager global configuration command. The no form of this command stops the SNMP manager process.

snmp-server manager

snmp-server manager session-timeout

To set the amount of time before a nonactive session is destroyed, use the snmp-server manager session-timeout global configuration command. The no form of this command returns the value to its default.

snmp-server manager
snmp-server manager session-timeout 1000
 
 
 
 
 
 

snmp-server packetsize

To establish control over the largest Simple Network Management Protocol packet size permitted when the SNMP server is receiving a request or generating a reply, use the snmp-server packetsize global configuration command. Use the no form of this command to restore the default value.

snmp-server packetsize 1024

snmp-server queue-length

To establish the message queue length for each trap host, use the snmp-server queue-length global configuration command.

snmp-server queue-length 4

snmp-server system-shutdown

To use the Simple Network Management Protocol message reload feature, the router configuration must include the snmp-server system-shutdown global configuration command. The no form of this command prevents an SNMP system-shutdown request (from an SNMP manager) from resetting the Cisco agent.

snmp-server system-shutdown
 

snmp-server tftp-server-list

To limit the TFTP servers used via Simple Network Management Protocol-controlled TFTP operations (saving and loading configuration files) to the servers specified in an access list, use the snmp-server tftp-server-list global configuration command. To disable this feature, use the no form of this command.

snmp-server tftp-server-list 44

snmp-server trap-authentication

The snmp-server enable traps snmp authentication command replaces this command. See the snmp-server host command in this chapter for more information.

snmp-server trap-source

To specify the interface (and hence the corresponding IP address) that an Simple Network Management Protocol trap should originate from, use the snmp-server trap-source global configuration command. Use the no form of the command to remove the source designation.

snmp-server trap-source ethernet 0
 

snmp-server trap-source ethernet 2/1

snmp-server trap-timeout

To define how often to try resending trap messages on the retransmission queue, use the snmp-server trap-timeout global configuration command.

snmp-server trap-timeout 20

snmp-server user

To configure a new user to an Simple Network Management Protocol group, use the snmp-server user global configuration command. To remove a user from an SNMP group, use the no form of the command.

Syntax Description

username	The name of the user on the host that connects to the agent.
groupname	(Optional) The name of the group to which the user is associated.
remote	(Optional) Specifies the remote copy of SNMP on the router.
ip-address	(Optional) The IP address of the device that contains the remote copy of SNMP.
udp-port	(Optional) Specifies a UDP port of the host to use.
port	(Optional) A UDP port number that the host uses. The default is 162.
v1	(Optional) The least secure of the possible security models.
v2c	(Optional) The second least secure of the possible security models. It allows for the transmission of informs and counter 64, which allows for integers twice the width of what is normally allowed.
v3	(Optional) The most secure of the possible security models.
encrypted	(Optional) Specifies whether the password appears in encrypted format (a series of digits, masking the true characters of the string).
auth	(Optional) Initiates an authentication level setting session.
md5	(Optional) The HMAC-MD5-96 authentication level.
sha	(Optional) The HMAC-SHA-96 authentication level.
auth-password	(Optional) A string (not to exceed 64 characters) that enables the agent to receive packets from the host.
priv	(Optional) The option that initiates a privacy authentication level setting session.
des56	(Optional) The CBC-DES privacy authentication algorithm.
priv password	(Optional) A string (not to exceed 64 characters) that enables the host to encrypt the contents of the message it sends to the agent.
access	(Optional) The option that enables you to specify an access list.
access-list	(Optional) A string (not to exceed 64 characters) that is the name of the access list.

Defaults

Table 46 describes default values for the encrypted option, passwords and access lists.
Table 46: snmp-server user Default Descriptions

Default	Description
encrypted	Not present by default. It is used to specify that the auth and priv passwords are MD5 digests and not text passwords.
passwords	Assumed to be text strings.
access lists	Access from all IP access lists is permitted.
remote users	All users are assumed to be local to this SNMP engine unless you specify they are remote with the remote option.

snmp-server view

To create or update a view entry, use the snmp-server view global configuration command. To remove the specified Simple Network Management Protocol server view entry, use the no form of this command.

Two standard predefined views can be used when a view is required, instead of defining a view. One is everything, which indicates that the user can see all objects. The other is restricted, which indicates that the user can see three groups: system, snmpStats, and snmpParties. The predefined views are described in RFC 1447.

snmp-server view mib2 mib-2 included
 

snmp-server view phred system included
snmp-server view phred cisco included
 

snmp-server view agon system included
snmp-server view agon system.7 excluded
snmp-server view agon ifEntry.*.1 included
 

snmp trap link-status

To enable Simple Network Management Protocol link trap generation, use the snmp trap link-status interface configuration command. To disable SNMP link traps, use the no form of this command.

interface bri 0
 no snmp trap link-status

Posted: Wed Aug 16 20:48:07 PDT 2000
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