VM65799: USE UNTAGGED FRAMES FOR NATIVE VLAN SWITCHOVER

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When a VLAN AWARE Layer2 VSWITCH (ETHERNET) is configured with
  a backup RDEV, CP automatically recovers from a failover by
  generating VLAN traffic for each virtual MAC.  However, guests
  using the NATIVE VLAN (typically VLAN 1) are often left without
  connectivity for a few minutes after failover (or SWITCHOVER).
  The time to full recovery varies with each instance.
  

Local fix

• Apply PTF
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: A VM user with a virtual NIC coupled to a    *
  *                 Layer2 VSWITCH may encounter a delay in      *
  *                 recovering connectivity on the NATIVE VLAN   *
  *                 after failover or switchover to a backup     *
  *                 OSA RDEV.                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  The NATIVE VLAN (typically VLAN 1) represents the untagged VLAN
  group.  CP does not register (SETVLAN) the NATIVE VLAN on the
  VSWITCH OSA connection.  When a NATIVE VLAN interface is
  initialized on the VSWITCH, all ARP activity for that virtual
  MAC address is untagged.  During failover (or switchover) CP
  sends gratuitous ARP frames to the new OSA RDEV for every
  interface but all of those frames are tagged (including the
  NATIVE VLAN interfaces).  Since the NATIVE VLAN is not
  registered on the OSA RDEV, current OSA microcode does not
  forward those tagged NATIVE VLAN frames to the external
  switch.  As a result, the switch continues to direct traffic
  for that virtual MAC to the old OSA device (until the ARP
  cache entry times out).
  

Problem conclusion

• Entry point HCPARPG0 generates the gratuitous ARP frame for
  failover (or switchover).  HCPARPG0 is updated to suppress the
  VLAN tag when generating the ARP frame to advertise a virtual
  MAC on the the NATIVE VLAN.
  

Temporary fix

• FOR RELEASE VM/ESA CP/ESA R620 :
  PREREQ: VM65560
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESA CP/ESA R630 :
  PREREQ: VM65560
  CO-REQ: NONE
  IF-REQ: NONE
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UM34772 UM34773

Modules/Macros

• HCPARP
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• R540 PSN

     UP

• R620 PSY UM34772

     UP16/03/30 I 1000

• R630 PSY UM34773

     UP16/03/30 P 1602

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.