5.170. lldpad

Bug Fix

BZ#844415

Previously, an error in the DCBX (Data Center Bridging Exchange) version selection logic could cause LLDPDUs (Link Layer Discovery Protocol Data Units) to be not encoded in the TLV (Type-Length Value) format during the transition from IEEE DCBX to the legacy DCBX mode. Consequently, link flaps, a delay, or a failure in synchronizing up DCBX between the host and a peer device could occur. In the case of booting from a remote FCoE (Fibre-Channel Over Ethernet) LUN (Logical Unit Number), this bug could result in a failure to boot. This update fixes the bug and TLV is now always used in the described scenario.

BZ#828684

Previously, dcbtool commands could, under certain circumstances, fail to enable the Fibre Channel over Ethernet (FCoE) application type-length-values (TLV) for a selected interface during the installation process. Consequently, various important features might have not been enabled (for example priority flow control, or PFC) by the Data Center Bridging eXchange (DCBX) peer. To prevent such problems, application-specific parameters (such as the FCoE application TLV) in DCBX are now enabled by default.

BZ#768555

The lldpad tool is initially invoked by initrd during the boot process to support Fibre Channel over Ethernet (FCoE) boot from a Storage Area Network (SAN). The runtime lldpad initscript did not kill lldpad before restarting it after system boot. Consequently, lldpad could not be started normally after system boot. In this update, lldpad init now contains the "-k" option to terminate the first instance of lldpad that was started during system boot.

BZ#803482

When the Data Center Bridging Exchange (DCBX) IEEE mode fails, it falls back to Converged Enhanced Ethernet (CEE) mode and Data Center Bridging (DCB) is enabled as part of the ifup routine. Normally, this does not occur unless either a CEE-DCBX Type-Length-Value (TLV) is received or the user explicitly enables this mode. However, in kernels released earlier than 2.6.38, DCBX IEEE mode is not supported and IEEE falls back to CEE mode immediately. Consequently, DCB was enabled in CEE mode on some kernels when IEEE mode failed, even though a peer TLV had not yet been received and the user did not manually enable it. This update fixes the logic by only enabling and advertising DCBX TLVs when a peer TLV is received. As a result, lldpad DCBX works as expected; IEEE mode is the default and CEE mode is used only if a peer CEE-DCBX TLV is received or the user enables it through the command line.

BZ#811422

A user may use dcbtool commands to clear the advertise bits on CEE-DCBX feature attributes (such as PFC, PG, APP). However, the user settings were lost during ifdown and ifup sequences and the default values were restored. This update fixes the problem so that the values are only set to defaults if the user has not explicitly enabled them.

Enhancement

BZ#812202

When a switch disassociated a connection for a virtual machine (VM) running on a host and the VM was configured to use 802.1Qbg, then libvirt was not informed and the VM connectivity was lost. Libvirt has support for restarting a VM, but it relies on the LLDP Agent Daemon to forward the Virtual Switch Interface (VSI) information. This update enables forwarding of the switch-originated VSI message to libvirt.