Configuring and Monitoring LAN Network Manager (LNM)

This document describes the LAN Network Manager (LNM). It includes the following sections:

About LNM

LNM lets you manage Token Ring networks interconnected by source route bridges. It lets you monitor the operation of rings, bridges and individual ring stations.

Information collected by software agents on the bridge is available to LNM management stations. More specifically, LNM agents forward collected information via another agent called the LAN Reporting Mechanism (LRM), a proprietary IBM protocol. Information forwarding is done via an LLC2 connection to a LAN Network Manager station.

LNM Agents and Functions

The LNM agents and their functions include the following:

Configuration Report Server (CRS) reports ring topology changes and ring station status to LNM.
Ring Parameter Server (RPS) services requests from ring stations for ring parameter information including ring number, the soft error report timer value, and the physical location.
Ring Error Monitor (REM) collects error reports from ring stations and analyzes them. When thresholds are exceeded, REM may forward error information to LNM.
LAN Reporting Mechanism (LRM) controls the establishment of reporting links from LNM stations to the bridge agents. Also manages the transfer of information to and from the other agents over these links.

Figure 1 illustrates the connection between the bridge, LNM agents, and the IBM LNM station.

Figure 1 LNM Station and Agents

The following sections describe each LNM agent in more detail.

Configuration Report Server

At the request of LNM, CRS obtains and forwards ring station status to LNM. You can also use CRS to set ring station parameters and remove a station from the ring.

Configuration information generated by ring stations is forwarded to LNM. When LNM requests the status of a ring station, CRS builds and sends MAC frames to the station to obtain the information. CRS then sends the following to the ring station:

Request Ring Station Address MAC frame
Request Ring Station State MAC frame
Request Ring Station Attachments MAC frame

When the ring station replies, CRS puts the information into a properly formatted LLC2 frame and forwards it to LNM.

CRS can also remove a ring station from the ring at the request of LNM. To remove a ring station, CRS sends a Remove Station MAC frame to the ring. CRS also returns a response to LNM indicating the success or failure of the removal.

When CRS receives a Report New Active Monitor MAC frame, it forwards the information to LNM. When a Report NAUN (Next Active Upstream Neighbor) Change MAC frame is received, this information is also reported. The CRS agent has its own functional address that ring station MAC layers can use to forward MAC frames to CRS.

Ring Parameter Server

RPS inserts ring stations onto the ring. When a ring station is newly inserted into the ring the following occurs:

The new station sends a Request Initialization MAC frame to RPS for that ring. This MAC frame includes some information about the station.
RPS responds with an Initialize Ring Station MAC frame containing the ring number and the interval of time to wait between sending Report Soft Error MAC frames. The information gleaned from the Request Initialization frame is passed to LNM so that it may maintain a database of all ring stations on the ring.
RPS also responds to a request for status from LNM. The ring number, RPS version information and the soft error report timer value are returned to LNM.

The RPS function has an associated functional address for receiving the MAC frames that other ring stations send to it.

Ring Error Monitor

REM observes the operation of the attached Token Ring by looking for hard errors and soft errors. It then reports these to LRM and aids in isolating the cause of the errors. It does the following during hard error detection:

Hard errors are detected on the ring by the receipt of Beacon MAC frames.
Stations in the fault domain attempt to correct the problem by possibly removing themselves from the ring.
REM determines if the hard error condition is corrected or not and then reports the results to LNM.

REM monitors soft errors as follows:

Ring stations periodically send Soft Error MAC frames to REM to inform it of the number of times various intermittent faults, for example, CRC errors and frequency errors occur.
When the number of soft errors for a station a certain threshold, REM reports this condition to LNM.
REM also monitors the Report Soft Error MAC frames for receiver congestion conditions. Receiver congestion indicates that a ring station discarded frames due to a shortage of receive buffers.
If the number of times a station reports receiver congestion exceeds a certain threshold, REM reports this condition to LNM. When the receiver congestion condition returns to normal, LNM is notified that the receiver congestion condition has ended.

LAN Reporting Mechanism

LRM controls the connection of LNM to the agents. LRM establishes reporting links between itself and each connected LNM. A reporting link is an LLC2 connection between LNM and LRM.

All communication between LNM and the agents is done via a reporting link. LRM passes management data to and from the appropriate agents to the reporting links. Up to four reporting links are supported. One is designated the controlling link and the other three are designated as observing links.

An LNM connected via the controlling link can perform all available operations. LNMs connected by observing links can perform only a limited subset of the available operations.

LNM Configuration Restrictions

The following restrictions apply to the LNM software:

The following platforms support multiport Token Ring and two Token Ring configurations: DNX 300, CNX 500, CNX 600, and RBX Series.

The LNM agent and the LNM station always assume that messages are being passed on a two-port model. LNM is enabled, however, on a per bridge port basis to be consistent with the existing Proteon configuration.
This is what is meant by a multiport configuration. LNM can be enabled on any source-routing Token Ring bridge port. In other words, an instance of LNM is created for each port upon which LNM is enabled.
With the exception of a two Token Ring configuration, the other port in a two-port model is always designated by a bogus address. This address corresponds to something that is not a real Token Ring interface. It can correspond to a virtual ring or a serial interface.
Only in the case where the Proteon bridge has two source-routing Token Ring ports is the other port in the two-port model bridge a Token Ring with a real address.
To obtain the MAC addresses needed to configure the LNM Manager, enter list lnm ports.
LBS (LAN Bridge Server) can report packets-forwarded and packets-discarded performance data statistics when requested by the manager station. Remote configuration updates from the manager station are not supported.
The Proteon LNM supports the IBM LAN Network Manager 1.1 and 2.0 products.

Logical Link Class 2 Support

In LANs, the data link layer comprises two sublayers: the Medium Access Control (MAC) and the Link Layer Control (LLC). LLC provides two types of service:

LLC1 (Type 1) - an unacknowledged connectionless service
LLC2 (Type 2) - a set of connection-oriented service

LAN Network Manager (LNM) requires LLC2 connection-oriented services. LLC2 provides capabilities for the following:

Initiating new data link connections
Managing data link connections
Exchanging data in sequential order (in a guaranteed fashion)
Executing a level of flow control on the established connections
Terminating link connections upon request from the service user or unrecoverable link errors.

The LLC sublayer conforms to the IEEE 802.5 standard.

Configuring LNM

This section summarizes the procedure necessary for basic configuration of the LNM feature.

1. Obtain the MAC address required for network manager software running on the Network Manager Station.

Enter list lnm ports at the Bridge> prompt.

Bridge>list lnm ports
Port Number [1]? 1
Port 1
LNM Agents Enabled: RPS CRS REM
Reporting Link          State          LNM Station Address
      0                 ACTIVE         10:00:5A:F1:02:37
      1                 AVAILABLE      
      2                 AVAILABLE      
      3                 AVAILABLE      
MAC Addresses to use when configuring LNM Manager:
      00:00:C9:08:35:47
      40:00:D9:08:35:47
LNM not enabled on port 4 
LNM not enabled on port 5

The Network Manager uses the MAC addresses displayed to configure it to the LNM agents present in the router.

Note: Enter these addresses exactly as they appear in the output or LNM will not configure correctly.

2. Enable the LNM agents on the router.

Enter enable lnm at the LNM config> prompt to enable the LNM agents on the desired port.

LNM config>enable lnm
Port Number [1]? 1

The default setting has all LNM agents enabled.

3. Check the configuration by displaying enabled LNM agents.

Enter list port at the LNM config> prompt to display which LNM agents are enabled on your configured port.

LNM config>list port
Port Number [1]? 1
LNM Agents Enabled: RPS CRS REM

LNM Commands

This section describes the LNM configuration and monitoring commands.

[C] means the command is available at the LNM config> prompt. Display this prompt as follows:

Config>protocol bridge
Transparent Bridge user configuration
Bridge Config>lnm
LNM configuration
LNM config>

[M] means the command is available at the LNM> prompt. Display this prompt as follows:

Monitor>protocol bridge
Bridge>lnm
LNM>

Table 1 lists the LNM commands. Not all parameters apply to all router platforms. Press Space after you type a command to display the available parameters for each command for your router. Enter help for information about using the command line interface.

Table 1 LNM Commands

Command Function

Disable [C] Disables all LNM agents or specified LNM agents (RPS, CRS, or REM) on a specified port.
Disables the setting of certain LNM parameters from the remote LNM application linked to the bridge. Applies globally to all instances of LNM within the bridge.

Enable [C] Enables all LNM agents or specified LNM agents (RPS, CRS, or REM) on a specified port.
Enables the setting of certain LNM parameters from the remote LNM application linked to the bridge. Applies globally to all instances of LNM within the bridge.

Exit [C] [M] Returns to the previous prompt.

List [C] [M] Displays the LNM agents that are enabled for the specified port. Displays the passwords configured for the bridge.

Set [C] Sets the password for the specified reporting link number.

Table 1 LNM Commands
Command	Function
Disable [C]	Disables all LNM agents or specified LNM agents (RPS, CRS, or REM) on a specified port. Disables the setting of certain LNM parameters from the remote LNM application linked to the bridge. Applies globally to all instances of LNM within the bridge.
Enable [C]	Enables all LNM agents or specified LNM agents (RPS, CRS, or REM) on a specified port. Enables the setting of certain LNM parameters from the remote LNM application linked to the bridge. Applies globally to all instances of LNM within the bridge.
Exit [C] [M]	Returns to the previous prompt.
List [C] [M]	Displays the LNM agents that are enabled for the specified port. Displays the passwords configured for the bridge.
Set [C]	Sets the password for the specified reporting link number.

Disable [C]

Disables all LNM agents on a port or disables specified LNM agents (CRS, REM, or RPS) on a port.

If the port is not configured then the message LNM not configured for Port XX is displayed. If this is the case, the command has no effect.

This command also disables the setting of the reporting link passwords from the remote LNM application linked to the bridge.

Syntax: disable

crs (Configuration Report Server)
rem (Ring Error Monitor)
rps (Ring Parameter Server)
lnm
configuration-remote-change

crs port#

Disables the LNM agent CRS on the specified port.

Example: disable CRS

Port Number [1]? 3

rem port#

Disables the LNM agent REM on the specified port.

Example: disable REM

Port Number [1]? 3
Already Disabled

rps port#

Disables the LNM agent RPS on the specified port.

Example: disable RPS

Port Number [1]? 3

lnm port#

Disables LNM on the specified port. If the port is not configured, the message LNM not configured for Port XX appears and the command has no effect.

If none of the LNM agents are enabled for the specified port, the message LNM not configured for Port XX appears.

Example: disable lnm

Port Number [1]? 1
LNM not configured for Port 1

configuration-remote-change

Disables the setting of the reporting link passwords from the remote LNM application linked to the bridge. This command applies globally to all instances of LNM within the bridge.

Example: disable configuration-remote-change

CONFIGURATION-REMOTE-CHANGE: Disabled

Enable [C]

Enables all LNM agents on a specified port or enables specified LNM agents (CRS, REM, or RPS) on a specified port.

This command also enables the setting of the reporting link passwords from the remote LNM application linked to the bridge.

Syntax: enable

crs (Configuration Report Server)
rem (Ring Error Monitor)
rps (Ring Parameter Server)
lnm
configuration-remote-change

crs port#

Enables the LNM agent CRS on the specified port.

Example: enable CRS

Port Number [1]? 10
Port number 10 does not exist

rem port#

Enables the LNM agent REM on the specified port.

Example: enable REM

Port Number [1]? 3
Already Enabled

rps port#

Enables the LNM agent RPS on the specified port.

Example: enable RPS

Port Number [1]? 1
Port number 1 is not Token Ring

lnm port#

Enables all LNM agents on the specified port.

If the port is not configured, the message Port number XX does not exist appears.

If the specified agent is already enabled for the port the message Already Enabled appears.

Example: enable lnm

Port Number [1]? 1

configuration-remote-change

Enables the setting of the reporting link passwords from the remote LNM application linked to the bridge. The default disables the setting of LNM configuration parameters remotely. This command applies globally to all instances of LNM within the bridge.

Example: enable configuration-remote-change

CONFIGURATION-REMOTE-CHANGE: Enabled

Exit [C] [M]

Use the exit command to return to the previous prompt.

Syntax: exit

Example: exit

List [C] [M]

Displays the LNM agents enabled for the specified port, and also displays passwords that have been configured for the bridge.

List [C]

Syntax: list

password
port

password

Displays the passwords that have been configured for the reporting links of the bridge. Displays whether or not the passwords may be changed by the remote LNM application.

Example: list password

Reporting Link     Password
     0             87654321
     1             MADRAS  
     2             ABC1234 
     3             123ABC  
CONFIGURATION-REMOTE-CHANGE: Disabled

port port#

Displays the LNM agents enabled for the specified port if the port is a Token Ring port supporting Source Routing Bridging.

Example: list port

Port Number [1]? 1
LNM Agents Enabled: RPS CRS REM

List [M]

Syntax: list

bridge
LNM ports
source-routing configuration

bridge

Displays whether LNM is enabled on a specific port.

Example: list bridge

Bridge ID (prio/add):  32768/00-00-00-00-00-38
Bridge state:          Enabled
UB-Encapsulation:      Disabled
Bridge type:           SR-TB
Bridge capability:     ASRT
Number of ports:       5
STP Participation:     IEEE802.1d on TB ports and IBM-8209 on SR ports                                                     
			        Maximum          
Port  Interface State MAC Address      Modes   MSDU  Segment  Flags
   1  FDDI/0      Up  AA-00-04-00-26-14    T    4491            RD
   2  TKR/0       Up  00-00-93-90-4C-F7    T    2096            RD
   3  TKR/1     Down  00-00-00-00-00-00 SR         0 223        RD,LE
   4  FDDI/1    Down  00-00-00-00-00-00    T       0            RD
   5  Eth/0     Down  AA-00-04-00-26-14            0            RD 

Flags:RE =IBMRT PC behaviour Enabled, RD = IBMRT PC behaviour Disabled
      LE = LNM Enabled, LD = LNM Disabled, LF = LNM Failed

SR bridge number:      8
SR virtual segment:    812
Adaptive segment:      214

lnm ports

Displays the configuration of the LNM ports.

Example: list lnm ports

LNM not enabled on port 1 
LNM not enabled on port 2 
Port 3
LNM Agents Enabled: RPS CRS REM
Reporting Link          State          LNM Station Address
      0                 AVAILABLE      
      1                 AVAILABLE      
      2                 AVAILABLE      
      3                 AVAILABLE      
MAC Addresses to use when configuring LNM Manager:
      00:00:00:00:00:00
      00:00:00:00:00:00
LNM not enabled on port 4 
LNM not enabled on port 5

source-routing configuration

Displays whether LNM is enabled on a specific port.

Example: list source-routing configuration

Bridge number:               8
Bridge state:                Enabled
Maximum STE hop count        14
Maximum ARE hop count        14
Virtual segment:             812

Port  Segment  Interface  State   MTU    STE Forwarding   LNM
   3  223      TKR/1     Enabled  4399   Auto            ENA
   -  214      Adaptive  Enabled  1470   Yes

Set [C]

Sets the password for the specified reporting link number. The link number can be 0, 1, 2 or 3. Link 0 is used for the controlling link. Links 1, 2, and 3 are used for observing links.

The password should consist of six to eight characters, and must match the password used by LNM when it establishes a reporting link with the bridge. If you do not set the password, it defaults to the string 00000000.

Syntax: set password link# password

Example: set password

Link Number [0]? 1
Enter new password :  [ABCDEFGH]? guesswho

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