Bug ID 882709: Traffic does not pass on tagged VLANs on VE configured on Hyper-V hypervisors

Last Modified: Jan 20, 2023

Bug Tracker

Affected Product:  See more info
BIG-IP Install/Upgrade, TMOS(all modules)

Known Affected Versions:
14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 14.1.4.3, 14.1.4.4, 14.1.4.5, 14.1.4.6, 14.1.5, 14.1.5.1, 14.1.5.2, 14.1.5.3, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1

Fixed In:
17.0.0, 16.1.2.2, 15.1.6.1

Opened: Feb 20, 2020
Severity: 3-Major

Symptoms

Traffic does not pass on tagged VLANs when a BIG-IP Virtual Edition (VE) is deployed on a Hyper-V hypervisor. This may manifest as traffic failing after an upgrade from earlier (unaffected) software versions. Note: This functionality worked as expected in v13.x and earlier, and if the same VE is downgraded to v13.x, VLAN tagging functionality is restored. This is due to an interoperability issue between RedHat Enterprise Linux (RHEL) and Microsoft Hyper-V, which seems to affect RHEL v7.3 and RHEL v7.5. Hyper-V on Windows Server 2016 and Windows Server 2012 do not seem to identify the version of the built-in LIS correctly on Centos 7.3 or Centos 7.5 (which are built on RHEL 7.3 and RHEL 7.5 respectively). Although there is a statement of support by Microsoft for VLAN tagging on RHEL 7.3 and 7.5 when running on Hyper-V, that functionality does not appear to work at present: Supported CentOS and Red Hat Enterprise Linux virtual machines on Hyper-V :: https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/Supported-CentOS-and-Red-Hat-Enterprise-Linux-virtual-machines-on-Hyper-V.

Impact

-- The system does not prevent you from configuring tagged VLANs, even though they do not pass traffic. -- Although upgrades complete and you can reboot into the new boot location (or you can set up on Hyper-V from scratch), traffic does not pass (into the guest) across VLANs that are tagged. Important: If using tagged VLANs on VE setups on Hyper-V is critical to your configuration, you might want to elect to postpone upgrading from a working, v12.x and v13.x release.

Conditions

-- BIG-IP VE is deployed on a Hyper-V hypervisor. -- VLAN configured in BIG-IP VE with tagged interfaces, e.g.: net vlan external { interfaces { 1.1 { tagged } } tag 4000 } -- At present, VLAN tagging on the v14.x and v15.x releases does not work because those releases are running on CentOS 7.3 and 7.5 respectively, which both are affected by the MS/RHEL interoperability issue. -- BIG-IP v12.x and v13.x use a different (older) CentOS version, so VLAN tagging works without issue on those releases.

Workaround

Essentially, there is no workaround in this release; you must reconfigure the virtual machine to use separate, untagged interfaces for each VLAN. Note: Although this is technically a problem between Hyper-V and the built-in LIS on RHEL 7.3/7.5, this issue is being tracked internally in this bug.

Fix Information

None

Behavior Change

In this release, traffic does not pass on tagged VLANs when a BIG-IP Virtual Edition (VE) is deployed on a Hyper-V hypervisor. This functionality worked as expected in v13.x and earlier, and if the same VE is downgraded to v13.x, VLAN tagging functionality is restored. Important: If using tagged VLANs on VE setups on Hyper-V is critical to your configuration, you might want to elect to postpone upgrading from a working, v12.x and v13.x release.