Table of Contents

1 SNMP Configuration· 1-1

SNMP Overview· 1-1

SNMP Operation Mechanism·· 1-1

SNMP Versions· 1-1

Supported MIBs· 1-2

Configuring Basic SNMP Functions· 1-3

Configuring Trap Parameters· 1-5

Configuring Basic Trap· 1-5

Configuring Extended Trap· 1-6

Enabling Logging for Network Management 1-6

Displaying and Maintaining SNMP· 1-7

SNMP Configuration Examples· 1-7

SNMP Configuration Examples· 1-7

2 RMON Configuration· 2-1

Introduction to RMON· 2-1

Working Mechanism of RMON· 2-1

Commonly Used RMON Groups· 2-1

RMON Configuration· 2-3

Displaying and Maintaining RMON· 2-3

RMON Configuration Examples· 2-4

 

 

 

SNMP Overview

The simple network management protocol (SNMP) is used for ensuring the transmission of the management information between any two network nodes. In this way, network administrators can easily retrieve and modify the information about any node on the network. In the meantime, they can locate faults promptly and implement the fault diagnosis, capacity planning and report generating.

As SNMP adopts the polling mechanism and provides basic function set, it is suitable for small-sized networks with fast-speed and low-cost. SNMP is based on user datagram protocol (UDP) and is thus widely supported by many products.

SNMP Operation Mechanism

SNMP is implemented by two components, namely, network management station (NMS) and agent.

l          An NMS can be a workstation running client program. At present, the commonly used network management platforms include QuidView, Sun NetManager, IBM NetView, and so on.

l          Agent is server-side software running on network devices.

An NMS can send GetRequest, GetNextRequest and SetRequest messages to the agents. Upon receiving the requests from the NMS, an agent performs Read or Write operation on the managed object (MIB, Management Information Base) according to the message types, generates the corresponding Response packets and returns them to the NMS.

When a network device operates improperly or changes to other state, the agent on it can also send trap messages on its own initiative to the NMS to report the events.

SNMP Versions

Currently, SNMP agent on the device supports SNMPv3, and is compatible with SNMPv1 and SNMPv2c.

SNMPv3 adopts user name and password authentication.

SNMPv1 and SNMPv2c adopt community name authentication. The SNMP packets containing invalid community names are discarded. SNMP community name is used to define the relationship between SNMP NMS and SNMP agent. Community name functions as password. It can limit accesses made by SNMP NMS to SNMP agent. You can perform the following community name-related configuration.

l          Specifying MIB view that a community can access.

l          Set the permission for a community to access an MIB object to be read-only or read-write. Communities with read-only permissions can only query the device information, while those with read-write permission can configure the device as well.

l          Set the basic ACL specified by the community name.

Supported MIBs

An SNMP packet carries management variables with it. Management variable is used to describe the management objects of the device. To uniquely identify the management objects of the device, SNMP adopts a hierarchical naming scheme to organize the managed objects. It is like a tree, with each tree node representing a managed object, as shown in Figure 1-1. Each node in this tree can be uniquely identified by a path starting from the root.

Figure 1-1 Architecture of the MIB tree

 

The management information base (MIB) describes the hierarchical architecture of the tree and it is the set defined by the standard variables of the monitored network devices. In the above figure, the managed object B can be uniquely identified by a string of numbers {1.2.1.1}. The number string is the object identifier (OID) of the managed object.

The common MIBs supported by devices are listed in Table 1-1.

Table 1-1 Common MIBs

MIB attribute	MIB content	Related RFC
Public MIB	MIB II based on TCP/IP network device	RFC 1213
	BRIDGE MIB	RFC 1493
		RFC 2675
	RIP MIB	RFC 1724
	RMON MIB	RFC 2819
	Ethernet MIB	RFC 2665
	OSPF MIB	RFC 1253
	IF MIB	RFC 1573
Private MIB	DHCP MIB	—
	QACL MIB
	MSTP MIB
	VLAN MIB
	IPV6 ADDRESS MIB
	MIRRORGROUP MIB
	QINQ MIB
	802.x MIB
	HGMP MIB
	NTP MIB
	Device management
	Interface management

 

Configuring Basic SNMP Functions

Because the configuration of SNMPv3 is quite different from that of SNMPv1 and SNMPv2c, their configuration procedures are described in two subsections.

Configuring basic SNMP functions for SNMPv1 or SNMPv2c

Follow these steps to configure basic SNMP functions for SNMPv1 or SNMPv2c:

To do…			Use the command…	Remarks
Enter system view			system-view	—
Enable SNMP agent			snmp-agent	Optional Disabled by default. You can enable SNMP agent by executing this command or any of the commands used to configure SNMP agent.
Set system information, and specify to enable SNMPv1 or SNMPv2c on the device			snmp-agent sys-info { contact sys-contact | location sys-location | version { { v1 | v2c | v3 }* | all } }	Required By default, the contact information for system maintenance is "Hangzhou, H3C Technology Co., Ltd.", the system location is "Hangzhou China", and the SNMP version is None.
Set a community name and access permission	Direct configuration	Set a community name	snmp-agent community { read | write } community-name [ acl acl-number | mib-view view-name ]*	Required l      You can set an SNMPv1/SNMPv2c community name through direct configuration. l      Indirect configuration is compatible with SNMPv3. The added user is equal to the community name for SNMPv1 and SNMPv2c. l      You can choose either of them as needed.
	Indirect configuration	Set an SNMP group	snmp-agent group { v1 | v2c } group-name [ read-view read-view ] [ write-view write-view ] [ notify-view notify-view ] [ acl acl-number ]
		Add a user to an SNMP group	snmp-agent usm-user { v1 | v2c } user-name group-name [ acl acl-number ]
Set the maximum size of an SNMP packet for SNMP agent to receive or send			snmp-agent packet max-size byte-count	Optional 1,500 bytes by default.
Set the device engine ID			snmp-agent local-engineid engineid	Optional By default, the device engine ID is “enterprise number + device information”.
Create/Update the view information			snmp-agent mib-view { included | excluded } view-name oid-tree [ mask mask-value ]	Optional By default, the view name is “ViewDefault” and OID is 1.

 

Configuring basic SNMP functions for SNMPv3

The device now supports the Advanced Encryption Standard (AES) for SNMPv3 to provide encryption. AES can provide higher security than the Data Encryption Standard (DES).

Follow these steps to configure basic SNMP functions for SNMPv3:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enable SNMP agent	snmp-agent	Optional Disabled by default. You can enable SNMP agent by executing this command or any of the commands used to configure SNMP agent.
Set system information and specify to enable SNMPv3 on the device	snmp-agent sys-info { contact sys-contact | location sys-location | version { { v1 | v2c | v3 }* | all } }	Required By default, the contact information for system maintenance is "Hangzhou, H3C Technology Co., Ltd.", the system location is "Hangzhou China", and the SNMP version is None.
Set an SNMP group	snmp-agent group v3 group-name [ authentication | privacy ] [ read-view read-view ] [ write-view write-view ] [ notify-view notify-view ] [ acl acl-number ]	Required
Encrypt a plain-text password to generate a cipher-text one	snmp-agent calculate-password plain-password mode { md5 | sha } { local-engineid | specified-engineid engineid }	Optional This command is used if password in cipher-text is needed for adding a new user.
Add a user to an SNMP group	snmp-agent usm-user v3 user-name group-name [ cipher ] [ authentication-mode { md5 | sha } auth-password [ privacy-mode { des56 | aes128 } priv-password ] ] [ acl acl-number ]	Required
Set the maximum size of an SNMP packet for SNMP agent to receive or send	snmp-agent packet max-size byte-count	Optional 1,500 bytes by default.
Set the device engine ID	snmp-agent local-engineid engineid	Optional By default, the device engine ID is “enterprise number + device information”.
Create or update the view information	snmp-agent mib-view { included | excluded } view-name oid-tree [ mask mask-value ]	Optional By default, the view name is “ViewDefault” and OID is 1.

 

 

Configuring Trap Parameters

Configuring Basic Trap

Trap messages refer to those sent by managed devices to the NMS without request. They are used to report some urgent and important events (for example, the rebooting of managed devices).

Note that basic SNMP configuration is performed before you configure basic trap.

Follow these steps to configure basic Trap:

To do…		Use the command…	Remarks
Enter system view		system-view	—
Enable the device to send Trap messages to NMS		snmp-agent trap enable [ configuration | flash | standard [ authentication | coldstart | linkdown | linkup | warmstart ]* | system | ]	Optional By default, a port is enabled to send all types of Traps.
Enable the port to send Trap messages	Enter port view or interface view	interface interface-type interface-number
	Enable the port or interface to send Trap messages	enable snmp trap updown
	Quit to system view	quit
Set the destination for Trap messages		snmp-agent target-host trap address udp-domain { ip-address } [ udp-port port-number ] params securityname security-string [ v1 | v2c | v3 {authentication | privacy } ]	Required
Set the source address for Trap messages		snmp-agent trap source interface-type interface-number	Optional
Set the size of the queue used to hold the Traps to be sent to the destination host		snmp-agent trap queue-size size	Optional The default is 100.
Set the aging time for Trap messages		snmp-agent trap life seconds	Optional 120 seconds by default.

 

Configuring Extended Trap

The extended Trap includes the following.

l          “Interface description” and “interface type” are added into the linkUp/linkDown Trap message. When receiving this extended Trap message, NMS can immediately determine which interface on the device fails according to the interface description and type.

l          In all Trap messages sent from the information center to the log server, a MIB object name is added after the OID field of the MIB object. The name is for your better understanding of the MIB object.

Follow these steps to configure extended Trap:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Configure extended Trap	snmp-agent trap ifmib link extended	Optional By default, the linkUp/linkDown Trap message adopts the standard format defined in IF-MIB. For details, refer to RFC 1213.

 

Enabling Logging for Network Management

Follow these steps to enable logging for network management:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enable logging for network management	snmp-agent log { set-operation | get-operation | all }	Optional Disabled by default.

 

 

Displaying and Maintaining SNMP

To do…	Use the command…	Remarks
Display the SNMP information about the current device	display snmp-agent sys-info [ contact | location | version ]*	Available in any view
Display SNMP packet statistics	display snmp-agent statistics
Display the engine ID of the current device	display snmp-agent { local-engineid | remote-engineid }
Display group information about the device	display snmp-agent group [ group-name ]
Display SNMP user information	display snmp-agent usm-user [ engineid engineid | username user-name | group group-name ]
Display Trap list information	display snmp-agent trap-list
Display the currently configured community name	display snmp-agent community [ read | write ]
Display the currently configured MIB view	display snmp-agent mib-view [ exclude | include | viewname view-name ]

 

SNMP Configuration Examples

SNMP Configuration Examples

Network requirements

l          As shown in Figure 1-2, an NMS and Switch A (SNMP agent) are connected through the Ethernet. The IP address of the NMS is 10.10.10.1 and that of the VLAN interface on Switch A is 10.10.10.2.

l          Perform the following configuration on Switch A: setting the community name and access permission, administrator ID, contact and location of Switch A, and enabling the device to sent trap messages.

Thus, the NMS is able to access Switch A and receive the trap messages sent by Switch A.

Figure 1-2 Network diagram for SNMP configuration

 

Network procedure

# Enable SNMP agent, and set the SNMPv1 and SNMPv2c community names.

<device> system-view

[device] snmp-agent

[device] snmp-agent sys-info version all

[device] snmp-agent community read public

[device] snmp-agent community write private

# Set the access right of the NMS to the MIB of the SNMP agent.

[device] snmp-agent mib-view include internet 1.3.6.1

# For SNMPv3, set:

l          SNMPv3 group and user

l          security to the level of needing authentication and encryption

l          authentication protocol to HMAC-MD5

l          authentication password to passmd5

l          encryption protocol to AES

l          encryption password to cfb128cfb128

[device] snmp-agent group v3 managev3group privacy write-view internet

[device] snmp-agent usm-user v3 managev3user managev3group authentication-mode md5 passmd5 privacy-mode aes128 cfb128cfb128

# Set the VLAN-interface 2 as the interface used by NMS. Add port GigabitEthernet 1/0/2, which is to be used for network management, to VLAN 2. Set the IP address of VLAN-interface 2 as 10.10.10.2.

[device] vlan 2

[device-vlan2] port Ethernet 1/0/2

[device-vlan2] quit

[device] interface Vlan-interface 2

[device-Vlan-interface2] ip address 10.10.10.2 255.255.255.0

[device-Vlan-interface2] quit

# Enable the SNMP agent to send Trap messages to the NMS whose IP address is 10.10.10.1. The SNMP community name to be used is “public”.

[device] snmp-agent trap enable standard authentication

[device] snmp-agent trap enable standard coldstart

[device] snmp-agent trap enable standard linkup

[device] snmp-agent trap enable standard linkdown

[device] snmp-agent target-host trap address udp-domain 10.10.10.1 udp-port 5000 params securityname public

Configuring the NMS

The device supports iMC NMS. SNMPv3 adopts user name and password authentication. When you use the iMC, you need to set user names and choose the security level in. For each security level, you need to set authorization mode, authorization password, encryption mode, encryption password, and so on. In addition, you need to set timeout time and maximum retry times.

You can query and configure the device through the NMS. For more information, refer to the corresponding manuals of network management products.

 

 

Introduction to RMON

Remote monitoring (RMON) is a kind of management information base (MIB) defined by Internet Engineering Task Force (IETF). It is an important enhancement made to MIB II standards. RMON is mainly used to monitor the data traffic across a network segment or even the entire network, and is currently a commonly used network management standard.

An RMON system comprises of two parts: the network management station (NMS) and the agents running on network devices. RMON agents operate on network monitors or network probes to collect and keep track of the statistics of the traffic across the network segments to which their ports connect, such as the total number of the packets on a network segment in a specific period of time and the total number of packets successfully sent to a specific host.

l          RMON is fully based on SNMP architecture. It is compatible with the current SNMP implementations.

l          RMON enables SNMP to monitor remote network devices more effectively and actively, thus providing a satisfactory means of monitoring remote subnets.

l          With RMON implemented, the communication traffic between NMS and SNMP agents can be reduced, thus facilitating the management of large-scale internetworks.

Working Mechanism of RMON

RMON allows multiple monitors. It can collect data in the following two ways:

l          Using the dedicated RMON probes. When an RMON system operates in this way, the NMS directly obtains management information from the RMON probes and controls the network resources. In this case, all information in the RMON MIB can be obtained.

l          Embedding RMON agents into network devices (such as routers, switches and hubs) directly to make the latter capable of RMON probe functions. When an RMON system operates in this way, the NMS collects network management information by exchanging information with the SNMP agents using the basic SNMP commands. However, this way depends on device resources heavily and an NMS operating in this way can only obtain the information about these four groups (instead of all the information in the RMON MIB): alarm group, event group, history group, and statistics group.

The device implements RMON in the second way. With an RMON agent embedded in, the device can serve as a network device with the RMON probe function. Through the RMON-capable SNMP agents running on the device, an NMS can obtain the information about the total traffic, error statistics and performance statistics of the network segments to which the ports of the managed network devices are connected. Thus, the NMS can further manage the networks.

Commonly Used RMON Groups

Event group

Event group is used to define the indexes of events and the processing methods of the events. The events defined in an event group are mainly used by entries in the alarm group and extended alarm group to trigger alarms.

You can specify a network device to act in one of the following ways in response to an event:

l          Logging the event

l          Sending trap messages to the NMS

l          Logging the event and sending trap messages to the NMS

l          No processing

Alarm group

RMON alarm management enables monitoring on specific alarm variables (such as the statistics of a port). When the value of a monitored variable exceeds the threshold, an alarm event is generated, which then triggers the network device to act in the way defined in the events. Events are defined in event groups.

With an alarm entry defined in an alarm group, a network device performs the following operations accordingly:

l          Sampling the defined alarm variables periodically

l          Comparing the samples with the threshold and triggering the corresponding events if the former exceed the latter

Extended alarm group

With extended alarm entry, you can perform operations on the samples of alarm variables and then compare the operation results with the thresholds, thus implement more flexible alarm functions.

With an extended alarm entry defined in an extended alarm group, the network devices perform the following operations accordingly:

l          Sampling the alarm variables referenced in the defined extended alarm expressions periodically

l          Performing operations on the samples according to the defined expressions

l          Comparing the operation results with the thresholds and triggering corresponding events if the operation result exceeds the thresholds.

History group

After a history group is configured, the device collects network statistics information periodically and stores the statistics information temporarily for later use. A history group can provide the history data of the statistics on network segment traffic, error packets, broadcast packets, and bandwidth utilization.

With the history data management function, you can configure network devices to collect history data, sample and store data of a specific port periodically.

Statistics group

Statistics group contains the statistics of each monitored port on the device. An entry in a statistics group is an accumulated value counting from the time when the statistics group is created.

The statistics include the number of the following items: collisions, packets with cyclic redundancy check (CRC) errors, undersize (or oversize) packets, broadcast packets, multicast packets, and received bytes and packets.

With the RMON statistics management function, you can monitor the use of a port and make statistics on the errors occurred when the ports are being used.

RMON Configuration

Before performing RMON configuration, make sure the SNMP agents are correctly configured. For the information about SNMP agent configuration, refer to Configuring Basic SNMP Functions.

Follow these steps to configure RMON:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Add an event entry	rmon event event-entry [ description string ] { log | trap trap-community | log-trap log-trapcommunity | none } [ owner text ]	Optional
Add an alarm entry	rmon alarm entry-number alarm-variable sampling-time { delta | absolute } rising_threshold threshold-value1 event-entry1 falling_threshold threshold-value2 event-entry2 [ owner text ]	Optional Before adding an alarm entry, you need to use the rmon event command to define the event to be referenced by the alarm entry.
Add an extended alarm entry	rmon prialarm entry-number prialarm-formula prialarm-des sampling-timer { delta | absolute | changeratio } rising_threshold threshold-value1 event-entry1 falling_threshold threshold-value2 event-entry2 entrytype { forever | cycle cycle-period } [ owner text ]	Optional Before adding an extended alarm entry, you need to use the rmon event command to define the event to be referenced by the extended alarm entry.
Enter Ethernet port view	interface interface-type interface-number	—
Add a history entry	rmon history entry-number buckets number interval sampling-interval [ owner text ]	Optional
Add a statistics entry	rmon statistics entry-number [ owner text ]	Optional

 

 

Displaying and Maintaining RMON

To do…	Use the command…	Remarks
Display RMON statistics	display rmon statistics [ interface-type interface-number | unit unit-number ]	Available in any view
Display RMON history information	display rmon history [ interface-type interface-number | unit unit-number ]
Display RMON alarm information	display rmon alarm [ entry-number ]
Display extended RMON alarm information	display rmon prialarm [ prialarm-entry-number ]
Display RMON events	display rmon event [ event-entry ]
Display RMON event logs	display rmon eventlog [ event-entry ]

 

RMON Configuration Examples

Network requirements

l          As shown in Figure 2-1, the Switch to be tested is connected to a remote NMS through the Internet. Ensure that the SNMP agents are correctly configured before performing RMON configuration.

l          Create an entry in the extended alarm table to monitor the information of statistics on the Ethernet port, if the change rate of which exceeds the set threshold, the alarm events will be triggered.

Figure 2-1 Network diagram for RMON configuration

 

Configuration procedures

# Add the statistics entry numbered 1 to take statistics on GigabitEthernet 1/0/1.

<device> system-view

[device] interface GigabitEthernet 1/0/1

[device-GigabitEthernet1/0/1] rmon statistics 1

[device-GigabitEthernet1/0/1] quit

# Add the event entries numbered 1 and 2 to the event table, which will be triggered by the following extended alarm.

[device] rmon event 1 log

[device] rmon event 2 trap 10.21.30.55

# Add an entry numbered 2 to the extended alarm table to allow the system to calculate the alarm variables with the (.1.3.6.1.2.1.16.1.1.1.9.1+.1.3.6.1.2.1.16.1.1.1.10.1) formula to get the numbers of all the oversize and undersize packets received by GigabitEthernet 1/0/1 that are in correct data format and sample it in every 10 seconds. When the change ratio between samples reaches the rising threshold of 50, event 1 is triggered; when the change ratio drops under the falling threshold, event 2 is triggered.

[device] rmon prialarm 2 (.1.3.6.1.2.1.16.1.1.1.9.1+.1.3.6.1.2.1.16.1.1.1.10.1) test 10 changeratio rising_threshold 50 1 falling_threshold 5 2 entrytype forever owner user1

# Display the RMON extended alarm entry numbered 2.

[device] display rmon prialarm 2

Prialarm table 2 owned by user1 is VALID.

  Samples type            : changeratio

  Variable formula : (.1.3.6.1.2.1.16.1.1.1.9.1+.1.3.6.1.2.1.16.1.1.1.10.1)

  Description             : test

  Sampling interval      : 10(sec)

  Rising threshold       : 100(linked with event 1)

  Falling threshold      : 10(linked with event 2)

  When startup enables  : risingOrFallingAlarm

  This entry will exist : forever.

  Latest value            : 0