Re: [nv-l] Switch Analyzer and Enterasys Switches

2005-05-10 07:45:54
Subject: Re: [nv-l] Switch Analyzer and Enterasys Switches
From: Michael Webb <mlwebb AT us.ibm DOT com>
To: nv-l AT lists.us.ibm DOT com
Date: Tue, 10 May 2005 07:44:42 -0400

The accuracy and completeness of IBM Tivoli Switch Analyzer’s layer 2 discovery depends primarily on the availability of enough accurate information accessible from the Bridge MIB forwarding tables and certain private MIBs. The switch must support the RFC 1493 Bridge MIB, which is the minimum requirement for switch management. So technically we support them all if they, in turn, support the MIBs we need for discovery.

Switches that support multiple VLANs often require an additional SNMP querying technique referred to as Community String Indexing (CSI). CSI is used to support Cisco switches with multiple VLANs. Other vendor switches that do not require CSI or access to private MIBs for VLAN support are also supported.

For non-Cisco vendors requiring CSI, discovery is restricted to only those ports in the default VLAN (usually VLAN 1). CSI is not supported in IBM Tivoli Switch Analyzer for non-Cisco switch devices.

Now back to your situation in particular. You stated that the Layer-2 Physical view does not show all the nodes attached to that switch. I guess this implies that some devices are attached to the switch in the Layer 2 Physical View. Correct?

Here is what you can try.

snmpwalk –c <community string> <switch IP address> dot1dBridge

Do all of the active ports on the switch show up in this query? If not, they you may have a non-Cisco switch that requires CSI (mentioned above). You can verify this by querying the switch again as follows:

snmpwalk –c <community [email protected]_ID> <switch IP address> dot1dBridge

Where VLAN_ID is an actual VLAN ID used by the switch. If you see ports in this output that were not available in the previous output, then CSI is required for this particular switch. However, ITSA does not support CSI for non-Cisco switches at this time.

Please let me know the results.

Michael Webb, IBM Tivoli
Email: mlwebb AT us.ibm DOT com

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[nv-l] Switch Analyzer and Enterasys Switches


We have NetView 7.1.4 FP3 on Windows2000. We have installed switch analyzer on that. For some reason the switch analyzer is not showing some Layer-2 options it shows on a Cisco switch. Like the Layer-2 Physical view does not shows all the nodes attached to that switch. Can any one help me out on this. Do i need to load vendor specific MIBs to get that information? or the Switch analyzer doesn't support Enterasys switches?


Usman Taokeer
Associate Network Architect

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