Smarts IP: False STP connections are formed between Switches in IP 9.4.1; There is no connection between two devices in actual topology/network. The devices are from different locations.
Article ID: 331882
Updated On:
Products
VMware Smart Assurance
Issue/Introduction
Symptoms:
We have received trunk cable alerts between two devices on Smarts. There is no connection between two devices in actual topology/network. Two devices are from different locations.
STP connections are created during post processing by <BASEDIR>/IP/smarts/rules/discovery/ic-post-stp-trunk.asl.
Smarts will loop through every STPNode, the DesignatedBridgeMAC must not belong to itself to form a connection.
This mechanism won't work good for VSS switches, as they have dynamic MAC/virtual MAC. In this case, MAC 00-08-E3-FF-FC-28 was part of both switches.
We have received trunk cable alerts between two devices on Smarts. There is no connection between two devices in actual topology/network. Two devices are from different locations.
STP connections are created during post processing by <BASEDIR>/IP/smarts/rules/discovery/ic-post-stp-trunk.asl.
Smarts will loop through every STPNode, the DesignatedBridgeMAC must not belong to itself to form a connection.
This mechanism won't work good for VSS switches, as they have dynamic MAC/virtual MAC. In this case, MAC 00-08-E3-FF-FC-28 was part of both switches.
Environment
VMware Smart Assurance - SMARTS
Cause
1. The two connected switches are VSS switch and hence they host virtual MACs that are unique to the individual VSS within.
2. Two independent switches can host the same MACs and when these devices are discovered in SMARTS topology, there is a likelihood for these switches to be connected through STP protocol and land up getting a wrong cable/Trunk cable connection between the VSS switches that are in different location/region.
2. Two independent switches can host the same MACs and when these devices are discovered in SMARTS topology, there is a likelihood for these switches to be connected through STP protocol and land up getting a wrong cable/Trunk cable connection between the VSS switches that are in different location/region.
Resolution
The following solution is available to resolve this issue.
In tpmgr_param.conf file, the flag "ExcludeVSSMACRange" is set to FALSE by default.
If we set this flag to TRUE, the "VSSMACRange" attribute present in the tpmgr-param.conf will be picked up and checked with the STPnodes BridgedMAC address and if there is match to any of the Identified virtualMAC patterns, then the connection creation will be avoided.
Below is the list of such identified virtualMAC patterns, it can be found in tpmgr-param.conf:
# VSSMACRange
# VSSMACRange is the MAC address range reserved for VSSSwitch. This range of MAC address would be
# excluded during STP post processing
VSSMACRange 00-08-E3-FF-FC-*|00-08-E3-FF-FD-*|00-08-E3-FF-FE-*|00-08-E3-FF-FF-*|5C-45-27-1A-*
Steps to be followed to set the "ExcludeVSSMACRange" flag:
1) Open tpmgr-param.conf file using sm_edit:
<Basedir>/IP/smarts/bin#sm_edit ../conf/discovery/tpmgr-param.conf
2) Search for ExcludeVSSMACRange, you will find below entry:
# ExcludeVSSMACRange
# ExcludeVSSMACRange This flag decides whether to exclude this VSS MAC Range during STP Post processing
# If this flag is set to TRUE, then the MAC address specified in VSSMACRange will be excluded
# during STP post processing.
# By default this value is set to FALSE
ExcludeVSSMACRange FALSE
3) Change the value of the flag to TRUE.
Ex: ExcludeVSSMACRange TRUE
4) Save and Exit the file.
5) Reload the conf file to domain with below command:
<Basedir>/IP/smarts/bin#sm_tpmgr -s <IP domain name> --load-conf=tpmgr-param.conf
Post the full discovery, the false connection should be removed.
In tpmgr_param.conf file, the flag "ExcludeVSSMACRange" is set to FALSE by default.
If we set this flag to TRUE, the "VSSMACRange" attribute present in the tpmgr-param.conf will be picked up and checked with the STPnodes BridgedMAC address and if there is match to any of the Identified virtualMAC patterns, then the connection creation will be avoided.
Below is the list of such identified virtualMAC patterns, it can be found in tpmgr-param.conf:
# VSSMACRange
# VSSMACRange is the MAC address range reserved for VSSSwitch. This range of MAC address would be
# excluded during STP post processing
VSSMACRange 00-08-E3-FF-FC-*|00-08-E3-FF-FD-*|00-08-E3-FF-FE-*|00-08-E3-FF-FF-*|5C-45-27-1A-*
Steps to be followed to set the "ExcludeVSSMACRange" flag:
1) Open tpmgr-param.conf file using sm_edit:
<Basedir>/IP/smarts/bin#sm_edit ../conf/discovery/tpmgr-param.conf
2) Search for ExcludeVSSMACRange, you will find below entry:
# ExcludeVSSMACRange
# ExcludeVSSMACRange This flag decides whether to exclude this VSS MAC Range during STP Post processing
# If this flag is set to TRUE, then the MAC address specified in VSSMACRange will be excluded
# during STP post processing.
# By default this value is set to FALSE
ExcludeVSSMACRange FALSE
3) Change the value of the flag to TRUE.
Ex: ExcludeVSSMACRange TRUE
4) Save and Exit the file.
5) Reload the conf file to domain with below command:
<Basedir>/IP/smarts/bin#sm_tpmgr -s <IP domain name> --load-conf=tpmgr-param.conf
Post the full discovery, the false connection should be removed.
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