Troubleshooting Microsoft Nlb Unicast Mode; Limitations And Restrictions; Disabling Automatic Static Mac Learning On Vethernet; Checking Status On A Vsm - Cisco Nexus 1000V Troubleshooting Manual

Troubleshooting Microsoft NLB Unicast Mode

S e n d d o c u m e n t c o m m e n t s t o n e x u s 1 k - d o c f e e d b a c k @ c i s c o . c o m .
Troubleshooting Microsoft NLB Unicast Mode
Microsoft Network Load Balancing (MS-NLB) is a clustering technology offered by Microsoft as part
of the Windows server operating systems. Clustering enables a group of independent servers to be
managed as a single system for higher availability, easier manageability, and greater scalability.
For more information about Microsoft Network Load Balancing. See this URL:
http://technet.microsoft.com/en-us/library/bb742455.aspx
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Limitations and Restrictions

A syslog is generated if one of the following configurations exists when you try to disable automatic
static MAC learning for MS-NLB because they do not support this feature:
•
•
•

Disabling Automatic Static MAC Learning on vEthernet

You must disable automatic static MAC learning before you can successfully configure NLB on
vEthernet (vEth).
In interface configuration mode use the following commands:
switch(config)# int veth 1
switch(config-if)# no mac auto-static-learn
In port profile configuration mode use the following commands:
switch(config)# port-profile type vethernet ms-nlb
switch(config-port-prof)# no mac auto-static-learn

Checking Status on a VSM

If the NLB unicast mode configuration does not function, check the status of the Virtual Supervisor
Module (VSM).
Confirm that no mac auto-static-learn is listed in the vEth and/or port profile configurations.
Cisco Nexus 1000V Troubleshooting Guide, Release 4.2(1)SV2(2.1)
11-12
PVLAN port
Ports configured with unknown unicast flood blocking (UUFB)
Ports configured with switchport port-security mac-address sticky
Chapter 11 Layer 2 Switching
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