RHBA-2012:0901 - Bug Fix Advisory

Topic

Updated lldpad packages that fix various bugs and provide an enhancement are now
available for Red Hat Enterprise Linux 6.

Description

The lldpad package provides the Link Layer Discovery Protocol (LLDP) Linux user
space daemon and associated configuration tools. It supports Intel's Link Layer
Discovery Protocol (LLDP) and provides Enhanced Ethernet support.

These updated lldpad packages includes fixes for the following bugs:

• 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#768555)

• 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#803482)

• 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. (BZ#811422)

In addition, these updated lldpad packages provide the following enhancement:

• 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. (BZ#812202)

All users of lldpad are advised to upgrade to this updated package, which fixes
these bugs and adds this enhancement.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 768555 - lldpad initscript does not kill lldpad before starting it
• BZ - 796850 - lldpad: DCBX: segfault may occur when clearing advertise bit
• BZ - 811422 - lldpad: CEE DCBX: advertise bits may be reset to defaults at init

CVEs

(none)

References

(none)