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Cisco Bug: CSCur27722 - vNIC Failover on Windows 2008R2 with NIC teaming only works first time

Last Modified

Nov 27, 2020

Products (1)

  • Cisco UCS Virtual Interface Card

Known Affected Releases

2.1(0.12) 2.1(0.9)

Description (partial)

Unexpected network connectivity loss to Windows 2008R2 SP1 host after its teamed NICs take multiple link flaps.

When the following criteria are met, you may experience a disruption in connectivity to a UCS blade behind the FI:
 - UCSM 2.2(2c)
 - B200M3 with VIC1240
 - Service Profile with 1 A-Side vNIC, 1 B-Side vNIC - no failover enabled.
 - NICs in Windows OS teamed with either: (driver
            enictool -c "eth0" "eth1" -m 3
            enictool -c "eth0" "eth1" -m 4  (Mode 4 - LACP - is not a recommended or supported configuration for B-series behind FI but exhibits same behavior here.)

 - Flap the A-Side, restore it. (works as expected)
 - Flap the B-Side, restore it. (works as expected)
 - Flap the A-Side again - connectivity loss. (Not expected.)
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