A fix is available
APAR status
Closed as program error.
Error description
When using IBM Communication Server for Linux with a VSwitch, packets may be dropped and incorrectly marked as TX Error. The interface being used is a SNA LLC2 port on IBM Communication server. The problem occurs when the guest interface is configured an Access port on a VLAN AWARE ETHERNET (layer 2) VSwitch. In this scenario, CP needs to insert the VLAN tag into the Ethernet frame before sending it through the Virtual Switch. The packet length is adjusted to account for the VLAN tag. In the case of very small LLC packets, a logic error turns it into a malformed packet that is dropped as an Error instead of being delivered to the destination (or transmitted via the uplink port).
Local fix
Apply PTF
Problem summary
**************************************************************** * USERS AFFECTED: All VSwitch users configured with Access * * ports using non-IP protocols. * **************************************************************** * PROBLEM DESCRIPTION: * **************************************************************** * RECOMMENDATION: APPLY PTF * **************************************************************** When very short packets are transmitted by an access port on a VLAN AWARE VSwitch, network packets may be incorrectly marked as TX error.
Problem conclusion
A logic error incorrectly incremented a pointer to the wrong value when inserting the VLAN tag for a network packet being transmitted from an Access port. This error only caused an issue with a short network packet, such as one used in the SNA LLC2 protocol. The setting of this pointer has been corrected.
Temporary fix
Comments
APAR Information
APAR number
VM66426
Reported component name
VM CP
Reported component ID
568411202
Reported release
710
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-07-30
Closed date
2020-08-28
Last modified date
2021-06-29
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UM35721 UM35722
Modules/Macros
HCPVQA
Fix information
Fixed component name
VM CP
Fixed component ID
568411202
Applicable component levels
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.
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Document Information
Modified date:
30 June 2021