RHBA-2015:1258 - Bug Fix Advisory

Topic

Updated dhcp packages that fix several bugs and add one enhancement are now available for Red Hat Enterprise Linux 6.

Description

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address. The dhcp packages provide a relay agent and ISC DHCP service required to enable and administer DHCP on a network.

This update fixes the following bugs:

• Previously, the DHCPv6 client was sometimes started to configure a network interface which was not fully loaded. Consequently, dhclient failed to run because the network interface did not have a link-local address yet, which the DHCPv6 client requires. This update adds a wait loop into dhclient-script, and dhclient no longer fails due to a missing link-local address. (BZ#1130804)
• When the dhcpd daemon was using a plain interface as well as an interface

configured as a VLAN trunk, and the dhcpd daemon was configured to listen only on the plain interface, it detected traffic also from VLAN networks, regardless of the configuration. As a consequence, dhcpd was generating incorrect responses. With this update, the bug has been corrected, and in the described scenario, dhcpd now ignores tagged requests, and thus generates correct responses. (BZ#1150587)

• When running the DHCPv6 relay agent and the "lower" interface was specified ("-l") on the command line before the "upper" interface ("-u"), message relaying did not work. The underlying source code has been fixed, and DHCPv6 relay agent now relays messages properly. (BZ#1151054)
• When a large number of nodes with InfiniBand network cards booted at the same time, some nodes were assigned duplicate IP addresses. With this update, generation of the xid field in DHCP messages sent by the client has been fixed for the xid fields to be unique, and nodes are now assigned unique IP addresses as expected. (BZ#1185075)
• Previously, attempting to run the dhcrelay and dhcrelay6 services simultaneously prevented the latter service from starting. The dhcrelay6 init script has been fixed, and running both dhcrelay and dhcrelay6 services no longer causes problems. (BZ#1187967)

In addition, this update adds the following enhancement:

• With this update, the dhcpd daemon is able to handle dhcp option 97 - Client Machine Identifier (pxe-client-id), so it is now possible to statically allocate an IP address for a particular client based on its identifier, sent in option 97. (BZ#1058674)

Users of dhcp are advised to upgrade to these updated packages, which fix these bugs and add this enhancement.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/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 for Scientific Computing 6 x86_64
• 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
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 1130804 - DHCPv6-only ifup-eth fails to even run dhclient -6 due to a link-local IPv6 address still being 'tentative'
• BZ - 1151054 - 'dhcrelay -6 -l <nic1> -u <nic2>' does not work
• BZ - 1187967 - Can't run dhcrelay and dhcrelay6 simultaneously

CVEs

(none)

References

(none)