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Simple Network Management Protocol (SNMP) is an application-layer Internet Protocol (IP) that allows network devices to exchange management information. SNMP enables network administrators to manage network performance, find and solve network problems, and plan for network growth. The Cisco ONS 15200 SNMP is a common platform that allows third-party network managers to access and interface with ONS 15200 systems.
The ONS 15200 SNMP uses the Command Line Interface to configure SNMP. The Command Line Interface must be running in order to execute SNMP commands.
SNMP defines a client/server relationship. The client program (called the network manager) makes virtual connections to a server program (called the SNMP agent) on a remote network device. The SNMP agent sends information to the network manager regarding the status of the device. The database, controlled by the SNMP agent, is referred to as the SNMP Management Information Base (MIB) and is a standard set of statistical and control values. Using private MIBs, SNMP extends the standard values with values specific to a particular agent. Directives issued by the network manager client to an SNMP agent consist of the identifiers of SNMP variables (referred to as MIB object identifiers or MIB variables), along with instructions to obtain or change the value for the identifier.
ONS 15200 SNMP uses two types of SNMP messages: Get and Trap. A Get request returns the value of a named object, and a Trap message is generated asynchronously by network devices that can notify a network manager of a problem apart from any polling of the device. Each of these message types fulfills a particular requirement of network managers.
This section explains how to connect a computer running the ONS 15200 SNMP to the ONS 15200 network. Connect to the ONS 15200 network directly through an ONS 15252 MCU or indirectly through third-party customer equipment attached to the network.
The following procedure describes how to connect directly to the ONS 15252 Multichannel Unit (MCU).
Step 1 Attach one end of a crossover Ethernet cable to the ETHER port on the Network Control Board module (NCB). The NCB module is located in Slot 17 on the right side of the MCU. The ETHER connection on the NCB module is a standard RJ-45 connector.
Step 2 Connect the other end of the crossover Ethernet cable to the Ethernet port on the computer being connected to the ONS 15200 network.
You can also retrieve system information from the ONS 15200 system by making an indirect connection to the ONS 15200. To make an indirect connection, connect the computer to a local area network (LAN) or wide area network (WAN) connected to the ONS 15200. Any computer in the extended network can be configured to retrieve system information from the ONS 15200 system.
The computer used to connect to the network must be configured to use the same subnet mask as the ONS 15200 system. The following procedure describes how to configure the subnet mask on a computer operating with a Windows 95 platform. Procedures for other operating systems are similar. Refer to the technical documentation provided with the operating system for more information.
Step 1 From the Windows task bar, click Start > Settings > Control Panel. The Control Panel window opens.
Step 2 Double-click Network in the Control Panel window. The Network window opens.
Step 3 Click Add. The Select Network Component Type window opens.
Step 4 Click Protocols. The Select Network Protocol window opens.
Step 5 Choose the appropriate manufacturer and network protocols.
Step 6 Click Add. The Network window opens.
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Note If the computer you are configuring is connected indirectly to the ONS 15200 network through a LAN or WAN, the network protocol must match the protocol of the LAN or WAN to which it is connected. |
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Note If you are connecting the computer directly to the ONS 15201, select Microsoft (the manufacturer) and TCP/IP (the network protocol) in the Network window. |
Step 7 Select the network component just installed from the The following network components are installed area of the Network window.
Step 8 Click Properties. The TCP/IP window opens.
Step 9 Click the IP Address tab.
Step 10 Click Specify an IP address.
Step 11 Type the IP address of the computer in the IP Address field.
Step 12 Type the subnet mask of the ONS 15200 network in the Subnet Mask field.
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Note The subnet mask for the computer must match the subnet mask assigned to the ONS 15200 network. |
Step 13 Click OK.
Use the Command Line Interface to configure the SNMP agent.
The following steps describe how to run the ONS 15200 SNMP application:
Step 1 Click Start > Run on the Windows taskbar. The Run window opens.
Step 2 Type TELNET in the Run box. If you know the IP address for the NCB module, type a space and then the IP address in the Run box.
Step 3 Click OK. A Telnet session appears.
Step 4 Click Connect > Remote System on the menu bar. The Connect window opens.
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Note If you typed an IP address in the Run box, the connection is already established. You have completed this procedure. |
Step 5 Type the IP address of the NCB module in the Host Name box.
Step 6 Select telnet from the Port list.
Step 7 Select VT100 from the TermType list.
Step 8 Click Connect. The command line appears.
The SNMP Agent starts automatically when the NCB module boots. Once the SNMP agent is configured, it is ready to serve requests from an SNMP manager. See the "Set Up SNMP Community Support" procedure and the "SNMP Trap Support" section.
To start the ONS 15200 SNMP, enter a user name and a password when prompted. User names and passwords must be validated before access to the database is granted.
If no users are defined in the database, press the Enter key twice to bypass the user name and password. This is intended for first time log on only. The first user must create at least one user with administrator privileges. The existence of users automatically disables the anonymous log on.
Multiple simultaneous log on attempts with the same user name are not allowed. The system will prompt you for another user name and password if the log on fails. See the "Logging into the CLI" procedure for more information on how to log into the CLI.
The Command Line Interface is now ready for SNMP configuration, which is described in the "Set Up SNMP Community Support" section and the "SNMP Trap Support" section.
An SNMP-managed network consists of three primary components: managed devices, agents, and management systems. A managed device is a network node that contains an SNMP agent and resides on a managed network. Managed devices collect and store management information and use SNMP to make this information available to management systems that use SNMP. Managed devices include routers, access servers, switches, bridges, hubs, computer hosts, and printers.
An agent is a software module that resides on a managed device. An agent has local knowledge of management information and translates that information into a form compatible with SNMP. The SNMP agent gathers data from the management information base (MIB), which is the repository for information about device parameters and network data. The agent can also send traps, or notification of certain events, to the manager. Figure 5-1 illustrates these SNMP operations.
A management system executes applications that monitor and control managed devices. Management systems provide the bulk of the processing and memory resources required for network management. One or more management systems must exist on any managed network. Figure 5-2 illustrates the relationship between the three key SNMP components.
The Cisco ONS 15200 supports SNMP Version 1 (SNMPv1) and SNMP Version 2c (SNMPv2c) traps and gets. SNMPv1 and SNMPv2 share many features, but SNMPv2c offers additional protocol operations. The SNMP MIBs in the ONS 15200 define alarms, traps, and status. Through SNMP, network management system (NMS) applications can query a management agent using a supported MIB.
Step 1 Enter the management mode by using the configure management at the Command Line Interface prompt.
Step 2 Type cd snmp at the prompt to go to the SNMP node.
Step 3 Use the create community command to create an SNMP Community Entry.
Step 4 Type name <my community> at the prompt to enter the community name. For a description of SNMP community names, see the "SNMP Community Names" section.
Step 5 Type Exit.
Step 6 Use the commit community command to save the configuration to nonvolatile memory.
Example 5-1 shows sample SNMP community input.
NCB:>configure management
Configure management
Mgmt:#create community mycommunity
Created 'mycommunity'
mycommunity:#name mycommunity
mycommunity:#exit
Mgmt:#commit community mycommunity
Mgmt:#exit
NCB:>
When trap receiver or community entries are added, deleted, or edited, the changes take place immediately. You do not need to restart the SNMP software.
Step 1 From the Command Line Interface, enter management mode using the configure management command.
Step 2 Type cd snmp at the command prompt to go to the SNMP node.
Step 3 Use the create trap command to create an SNMP trap destination entry.
Step 4 Type ipaddress <ipaddress>.
Step 5 Type community mycommunity at the prompt.
Step 6 Type Exit.
Step 7 Use the commit trap command to save the configuration to nonvolatile memory.
Use the Show Management command to view SNMP information for each node.
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Note The UDP port for SNMP is 162. |
Example 5-2 shows sample SNMP trap input.
NCB:>configure management
Mgmt:#create trap mytrap
Created 'mytrap'
mytrap:#ipaddress 10.52.18.220
mytrap:#community mycommunity
mytrap:#list value
mytrap:
ipaddress 10.52.18.220
community mycommunity
mytrap:#exit
Mgmt:#commit trap mytrap
Mgmt:#exit
NCB:>
A Management Information Base (MIB) is a hierarchically-organized collection of information. MIBs are accessed using a network management protocol such as SNMP. MIBs consist of managed objects and are identified by object identifiers.
The ONS 15200 SNMP manager uses information in the MIB to perform the operations described in Table 5-1.
| Operation | Description |
|---|---|
get-request | Retrieve a value from a specific variable |
get-next-request | Retrieve the value following the named variable; this operation is often used to retrieve variables from within a table1 |
get-response | The reply to a get-request, get-next-request, get-bulk-request, or set-request sent by an NMS |
get-bulk-request | Similar to the get-next-request, but fill the get-response with up to the max-repetition number of get-next interactions |
trap | An unsolicited message sent by an SNMP agent to an SNMP manager indicating that an event has occurred |
A managed object (sometimes called an MIB object) is one of any number of specific characteristics of a managed device. Managed objects consist of one or more object instances that are, essentially, variables.
The ONS 15200 MIBs ship on the accompanying software CD. These MIBs need to be compiled in the following order. If the order is not followed, one or more MIB files may not compile:
If you are unable to compile the ONS 15200 MIBs, call the Cisco Technical Assistance Center (TAC) at 1-877-323-7368. Table 5-2 shows the Internet Engineering Task Force (IETF) standard MIBs and their associated module names.
| RFC# | Module Name | Title/Comments |
|---|---|---|
1213 +1907 | RFC1213-MIB, SNMPV2-MIB | MIB-II from RFC1213 with enhancement from RFC1907 for v2 |
2037 | ENTITY-MIB | Entity MIB using SMI v2 |
2233 | IF-MIB | Interface evolution (enhances MIB-II) |
The ONS 15200 can send traps and also receive SNMP requests from a number of SNMP managers. The ONS 15200 generates all alarms and events as SNMP traps.
Traps generated by the ONS 15200 contain an object ID that uniquely identifies the alarm. An entity identifier uniquely identifies which entity generated the alarm. Traps give the severity of the alarm (critical, major, minor, etc.) and a date/time stamp that shows the date and time the alarm occurred. Traps also contain a trap notification number, which is a sequential number that starts at one for the first generated trap and increases by one for each subsequent trap. The ONS 15200 also generates a trap for each alarm when the alarm condition clears.
The generic traps are listed in Table 5-3.
| Trap | From RFC# | IETF Standard Objects in Varbind List | Description |
|---|---|---|---|
ColdStart | RFC1213-MIB | None | Agent up - cold start |
WarmStart | RFC1213-MIB | None | Agent up - warm start |
AuthenticationFailure | RFC1213-MIB | None | Community string did not match |
Community names can be provisioned for all SNMP requests (see the "SNMP Trap Support" section). In effect, any SNMP request using a community name that matches a community name on the list of provisioned SNMP trap destinations is considered valid. Otherwise, the request is considered invalid and is dropped.
If an SNMP request contains an invalid community name, the request is silently dropped and the MIB variable, snmpInBadCommunityNames, is incremented. All SNMP requests containing a validated community name are granted access to all MIB variables managed by the agent.
Posted: Mon Sep 30 20:32:34 PDT 2002
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