1.40. dhcp

Updated dhcp packages that fix two security issues are now available for Red Hat Enterprise Linux 4, 5, and 6.
The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) associated with each description below.
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.

Security Fixes

CVE-2011-2748, CVE-2011-2749
Two denial of service flaws were found in the way the dhcpd daemon handled certain incomplete request packets. A remote attacker could use these flaws to crash dhcpd via a specially-crafted request.
Users of DHCP should upgrade to these updated packages, which contain a backported patch to correct these issues. After installing this update, all DHCP servers will be restarted automatically.
Updated dhcp packages that fix several bugs and add various enhancements are now available for Red Hat Enterprise Linux 6.
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.
Bug Fixes
BZ#625846
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#627257
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#631071
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#637763
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#672551
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#681721
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#613683
Previously, the dhclient package was missing its LICENSE file. With this update, the file has been added.
Enhancements
BZ#558641
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#660681
The dhcp package now provides support for IPoIB (IP over InfiniBand) interfaces.
Users of dhcp are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.