Cisco Systems BC-109 Disable Automatic Report Path Trace Function, trace function, lnm snmp-only

Configure LNM Support

The command can be used to terminate all LNM server input and reporting links. In normal circumstances, this command should not be necessary because it is a superset of the functions normally performed on individual interfaces by the no lnm rem and no lnm rps commands.

Disable Automatic Report Path Trace Function

Under some circumstances, such as when new hardware has been introduced into the network and is causing problems, the automatic report path trace function can be disabled. The new hardware may be setting bit-fields B1 or B2 (or both) of the routing control field in the routing information field embedded in a source-route bridged frame. This condition may cause the network to be flooded by report path trace frames if the condition is persistent. The lnm pathtrace-disabledcommand, along with its options, allows you to alleviate network congestion that may be occurring by disabling all or part of the automatic report path trace function within LNM.

To disable the automatic report path trace function, use the following command in global configuration mode:

Command	Purpose
lnm pathtrace-disabled [all origin]	Disable LNM automatic report path
	trace function.

Prevent LNM Stations from Modifying Cisco IOS Software Parameters

Because there is now more than one way to remotely change parameters in a router (either using SNMP or the proprietary IBM protocol), some method is needed to prevent such changes from detrimentally interacting with each other.You can prevent any LNM station from modifying parameters in the Cisco IOS software. It does not affect the ability of LNM to monitor events, only to change parameters on the router.

To prevent the modification of Cisco IOS software parameters by an LNM station, use the following command in global configuration mode:

Command	Purpose
lnm snmp-only	Prevent LNM stations from
	modifying LNM parameters in the
	Cisco IOS software.

Enable Other LRMs to Change Router Parameters

LNM has a concept of reporting links and reporting link numbers. A reporting link is simply a connection (or potential connection) between a LAN Reporting Manager (LRM) and a bridge. A reporting link number is a unique number used to identify a reporting link. An IBM bridge allows four simultaneous reporting links numbered 0 through 3. Only the LRM attached on the lowest-numbered connection is allowed to change LNM parameters in the router, and then only when that connection number falls below a certain configurable number. In the default configuration, the LRM connected through link 0 is the only LRM that can change LNM parameters.

BC-130Bridging and IBM Networking Configuration Guide