RHBA-2011:0697 - Bug Fix Advisory

Topic

Updated dhcp packages that fix several bugs and add various enhancements 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.
DHCPv6 is the DHCP protocol version for IPv6 networks.

This update fixes the following bugs:

• Previously, it was impossible to configure the dhcrelay service to run the

dhcrelay daemon with additional arguments. With this update, a DHCRELAYARGS
variable is available for the /etc/sysconfig/dhcrelay configuration file, which
allows additional arguments to be passed to the dhcrelay daemon properly.
(BZ#625846)

• Previously, the dhclient utility did not log its PID (process identifier) in

syslog entries, making troubleshooting in systems with multiple running
dhclients difficult. Now, the dhclient utility logs its PID properly.
(BZ#627257)

• Previously, the dhclient utility sometimes parsed date strings in lease files

incorrectly, resulting in syntax error messages in its output. This bug has been
fixed and the dates in the lease files are now parsed with no error messages
given. (BZ#631071)

• When the dhclient utility was updating a "search" entry in the

/etc/resolv.conf file, it sometimes did not add a missing domain part. This was
inconsistent with NetworkManager behavior. Now, while updating the "search"
entry, the dhclient utility always adds the domain part of the host name given
to the client if it is missing. (BZ#637763)

• Previously, the dhcpd service with IPv6 support sometimes created a lease file

that it was unable to parse. Consequently, once the service was restarted, it
went into a loop and could not start. This bug has been fixed and now the
service is able to properly parse all lease files it generates. (BZ#672551)

• DHCP servers at some ISPs send to clients the "interface-mtu" option with the

value of 576. Such a low MTU (Maximum Transmission Unit) can cause throughput
problems with UDP traffic, among other things. With this update, the dhclient
utility now sets the interface MTU only if the value obtained from the server is
higher than 576. (BZ#681721)

• Previously, the dhclient package was missing its LICENSE file. With this

update, the file has been added. (BZ#613683)

This update adds the following enhancements:

• The dhcp package now provides an implementation of Classless Static Route

Options for DHCPv4 (RFC 3442). It can supply network route configuration to a
large number of hosts without individual configuration of each one. (BZ#558641)

• The dhcp package now provides support for IPoIB (IP over InfiniBand)

interfaces. (BZ#660681)

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

Solution

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

This update is available via Red Hat Network. Details on how to use the Red
Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• 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 (for IBM z Systems) 6 s390x

Fixes

• BZ - 613683 - dhclient subpackage must include a copy of license text
• BZ - 625846 - Can't add extra arguments to dhcrelay daemon
• BZ - 627257 - dhclient should log pid in syslog
• BZ - 631071 - dhclient complains of syntax errors in lease file
• BZ - 660681 - (Mellanox6.1) Add IPoIB support in DHCP
• BZ - 672551 - DHCPv6 server creates a lease file that it cannot parse
• BZ - 681721 - dhclient sets MTU to 576 for addresses obtained via DHCP

CVEs

(none)

References

(none)