Configuring SNMP
SUMMARY: This document describes the Lucent implementation of the Simple
Network Management Protocol (SNMP) and includes the following topics:
Introduction
SNMP is an application-layer protocol that allows devices to
communicate management information. You can configure the PortMaster to provide network
and device information via SNMP to a network management system (NMS). You must have NMS
software to use SNMP.
SNMP has the following parts:
- An SNMP agent (provided in ComOS)
- An SNMP manager (not provided)
- A Management Information Base (MIB)
SNMP specifies the message format for exchanging information between
the SNMP manager and an SNMP agent.
The SNMP agent returns values for MIB variables that can be changed
or queried by the SNMP manager. The agent gathers information from the MIB, which resides
on the target device. MIB information can include device parameters and network status.
The agent is capable of responding to requests to get or set data from the manager.
Lucent products support both MIB I and MIB II variables as
specified in RFC 1213, along with an enterprise-specific MIB. SNMP management can be
enabled for any PortMaster (TM). Lucent ships configuration files compatible with various
network management packages along with the PMConsole (TM) software.
The livingston.mib Definition File
livingston.mib is the Lucent MIB definitions file SNMP
tools can read and use to query SNMP agents for information about PortMaster products. The
Lucent extensions to the MIB are located in the latter part of this file.
MIB files can be found in the SNMP directory of the ComOS
software, on the web at: ftp://ftp.livingston.com/pub/le/snmp. Use the readme file there
for further information.
The SNMP manager queries the agent by means of Object Identifiers,
or OIDs, which are numbers associated with the objects defined in the MIB. For example, to
set or return information on serial port S0 on a particular PortMaster, the request must
contain an OID that uniquely identifies the port in the Lucent name space, which is 307
(see Figure 2-1).
Note ¯ The full OID to get to the Lucent area is
1.3.6.1.4.1.307.
livingston.mib structure.In this example, the OID for serial port S0 is 307.3.2.1.1.1.2.0,
which breaks out as follows:
- 307 refers to the Lucent namespace
- 3 refers to the MIB
- 2 refers to interfaces
- 1 refers to serial interfaces
- 1 refers to the serial interfaces table
- 1 refers to an entry in the Lucent serial table (see Table
2-3)
- 2 refers to the port name
- 0 refers to the S0 port
A request containing this OID returns the port name assigned to port
S0. Table 2-3, shows a partial view of the Lucent serial table, which is read top to
bottom, left to right. The port name (reading down the left column) is identified first,
then (reading across) the port number.
As another example, OID 307.3.2.1.1.1.5.2 returns the session
identifier on port S2.
Lucent Serial Table.
|
S0 (0) |
S1 (1) |
S2 (2) |
S3 (3) |
S4 (4) |
1 |
Index |
Index |
Index |
Index |
Index |
2 |
PortName |
PortName |
PortName |
PortName |
PortName |
3 |
PhysType |
PhysType |
PhysType |
PhysType |
PhysType |
4 |
User |
User |
User |
User |
User |
5 |
SessionId |
SessionId |
SessionId |
SessionId |
SessionId |
6 |
Type |
Type |
Type |
Type |
Type |
7 |
Direction |
Direction |
Direction |
Direction |
Direction |
Lucent Serial Interfaces
Table 2-4 lists serial interface information from the Lucent
Extension section of the Lucent MIB. Note that modem-specific objects apply to the
PortMaster 3 only.
Serial Interface Table
Object |
Definition |
Index |
A unique value for each serial interface. |
PortName |
A text string containing the name of the serial interface (for
example, S0, W1, and so on). |
PhysType |
The type of physical serial interface, distinguished according to
the physical/link protocol (s) being currently used on the interface. |
User |
Name of the active user. Blank if not active. |
SessionId |
A unique session identifier that matches the RADIUS (TM) session
ID. |
Type |
The active type of service being provided by the serial interface. |
Direction |
The direction in which the active session was initiated. |
PortStatus |
The status of the serial interface. |
Started |
The amount of time this session has been active. |
Idle |
The amount of time this session has been idle. |
InSpeed |
An estimate of the current inbound bandwidth in bits per second of
the serial interface. |
OutSpeed |
An estimate of the current outbound bandwidth in bits per second
of the serial interface. |
ModemName
(PM3 only) |
A text string containing the name of the true digital modem in use
by the serial interface. |
IpAddress |
The IP address associated with the serial interface. When used as
a network type port, this is the IP address of the remote user. When used as a device or
login, this is the IP address of the host to which the user is connected. |
ifDescr |
A text string containing information about the network interface
bound to the serial interface. |
InOctets |
The total number of octets received on the serial interface. |
OutOctets |
The total number of octets transmitted on the serial interface. |
QOctets |
The total number of octets queued on the serial interface. |
ModemStatus |
The status of the modem used by the serial interface. |
ModemCompression (PM-3 only) |
The compression being used in the modem or by the serial
interface. |
ModemProtocol
(PM-3 only) |
The error correcting protocol being used in the modem or by the
serial interface. |
ModemRetrains
(PM-3 only) |
The number of retrains attempted by the modem attached to the
serial interface. |
ModemRenegotiates (PM-3 only) |
The number of renegotiations attempted by the modem attached to
the serial interface. |
Lucent T1/E1 Interfaces
Table 2-5 lists T1/E1 interface information from the Lucent
Extension section of the LUcent MIB. T1/E1 interfaces are supported on the
PortMaster 3 and PortMaster 4 Integrated Access Servers.
T1/E1 Interfaces
Object Type |
Definition |
Index |
A unique value for each T1/E1 interface. |
PhysType |
The type of interface (T1 or E1). |
Function |
The configured function of the interface |
Status |
The current operational status of the interface. Operational
status states and their ID numbers include the following:
- up (1)
- down (2)
- loopback (3)
|
Framing |
The configured line framing. Line framing types and their ID
numbers include the following:
- esf (1)
- d4 (2)
- crc4 (3)
- fas (4)
|
Encoding |
The configured line signal encoding. |
PCM |
The configured voice modulation. |
ChangeTime |
The amount of time this interface has been up or down. |
RecvLevel |
An estimate of the current receive signal level, in DB, of the
interface. |
BlueAlarms |
The total number of blue alarms on the interface. |
YellowAlarms |
The total number of yellow alarms on the interface. |
CarrierLoss |
The total number of times the interface has lost carrier. |
SyncLoss |
The total number of times the interface has lost frame
synchronizations. |
BipolarErrors |
The total number of frame level CRC errors detected on the
interface. |
CRCErrors |
The total number of frame level CRC errors detected on the
interface. |
SyncErrors |
The total number of frame synchronization errors detected on the
interface. |
Lucent Modem Table
Table 2-6, lists modem information from the Lucent Extension
section of the Lucent MIB. Modem objects are supported only on the PortMaster 3
Integrated Access Server.
Modem Table
Object Type |
Definition |
livingstonModemIndex |
A unique value for each modem interface. |
livingstonModemPortName |
A textual string containing the name of the serial interface (ie.
S0, S1, etc.). |
livingstonModemStatus |
A current state of the modem. |
livingstonModemProtocol |
The error correcting protocol being used in the modem. |
livingstonModemCompression |
The compression being used in the modem interface. |
livingstonModemInSpeed |
An estimate of the modem interface's current inbound bandwidth in
bits per second. |
livingstonModemOutSpeed |
An estimate of the modem interface's current outbound bandwidth in
bits per second. |
livingstonModemInByteCount |
The total number of bytes received by the modem. |
livingstonModemOutByteCount |
The total number of bytes transmitted by the modem. |
livingstonModemRetrains |
The number of retrains attempted by the modem. |
livingstonModemRenegotiates |
The number of renegotiations attempted by the modem. |
livingstonModemCalls |
The number of times a call received by the modem. |
livingstonModemDetects |
The number of analog calls received by the modem. |
livingstonModemConnects |
The number of successful calls received by the modem. |
Setting SNMP Monitoring
SNMP monitoring is used to set and collect information on SNMP
capable devices. This feature is most often used to monitor network statistics such as
usage and error rate.
If the SNMP monitoring is on, the PortMaster accepts SNMP queries.
If this parameter is off, all SNMP queries are ignored.
To turn SNMP monitoring on or off, use the following commands:
Command> set snmp on|off
Command> save all
Command> reboot
Setting SNMP Read and Write Community Strings
Community strings allow you to control access to the MIB
information on selected SNMP devices. The read and write community strings act like
passwords to permit access to the SNMP agent information. The read community string must
be known by any device allowed to access or read the MIB information. The default read
community string is public. The write community string must be known by any device
before information can be set on the SNMP agent. The default write community string is private.
Community strings should be set on SNMP agents so that configuration information is not
changed by unauthorized users.
To use this feature, you must set both a read community string and
a write community string for your network.
To set SNMP read and write community strings, use the following
command:
Command> set snmp readcommunity|writecommunity
String
Note ¯ Use of the default write community string-private-is strongly
discouraged. Because it is the default, it is known to all users and therefore provides no
security. You should use some other value for the write community string.
Adding SNMP Read and Write Hosts
PortMaster products allow you to control SNMP security by
specifying the IP addresses of the hosts that are allowed to access SNMP information. The
specification of read and write hosts allows another level of security beyond the
community strings. If SNMP hosts are specified, each host wanting to access SNMP
information must not only possess the correct community string, it must also be on the
read or write host list. This additional level of security allows only authorized SNMP
managers to access or change sensitive MIB information.
You can also specify a list of hosts allowed to read or write SNMP
information. You can permit all hosts (not recommended because this setting reduces system
security), or you can deny all hosts.
To add SNMP read and write hosts, use the following command:
Command> add snmphost reader|writer any|none|Ipaddress
To delete read and write hosts, use the following command:
Command> delete snmphost reader|writer
Ipaddress
Viewing SNMP Settings
Settings for SNMP monitoring, read and write community strings, and
read and write hosts are stored in the SNMP table.
To display the SNMP table, use the following command:
Command> show table snmp
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