802.1q tagged frames unable to traverse a router

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Environment

IBM zVM Hypervisor
SUSE Linux Enterprise Server 11 Service Pack 2 (SLES 11 SP2)
802.1q VLAN configuration

Situation

A SLES 11 SP2 guest on an IBM zVM Hypervisor configured with 802.1q VLAN tagging on an interface is unable to traverse a router. All frames destined for the broadcast domain work just fine, but anything destined outside of the network fails.

Communication to hosts within the same broadcast domain works properly.

Resolution

Update to SLES 11 SP3

Cause

There is an issue with the QDIO driver where the QDIO header incorrectly sets the destination address of the end node as opposed to the router (gateway) that forwards it along.

If this issue was manifest in a non-virtual networking environment, it would be as if the layer 2 header was destined for the hardware address of the final end node as opposed to the router (gateway).

This issue is specific to the environment section above, and does not apply to physical hosts.

Additional Information

Disclaimer

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