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8.30. dhcp

Updated dhcp packages that fix several bugs 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. The dhcp packages provide a relay agent and ISC DHCP service required to enable and administer DHCP on a network.

Bug Fixes

BZ#996518
Previously, the dhcpd daemon or the dhclient utility terminated unexpectedly with a segmentation fault when starting on an InfiniBand network interface card (NIC) with an alias interface and a shared-network defined. Consequently, dhcpd and dhclient could not be used with an alias interface in a different subnet on InfiniBand NICs. A patch has been applied to address this problem, and neither dhcpd nor dhclient now crash in this scenario.
BZ#902966
Prior to this update, if some of the IPv6 addresses were not in the subnet range declared by subnet6 in the range6 statement, the DHCPv6 server incorrectly offered an address which was not from the client's subnet. The range6 statement parsing code has been fixed to check whether its addresses belong to the subnet, in which the range6 statement was declared. With this update, the DHCPv6 server now fails to start with an error message if the range6 statement is incorrect.
BZ#863936
Previously, the DHCPv4 relay agent (dhcrelay) terminated unexpectedly with a segmentation fault if dhcrelay received a packet over an interface without any IPv4 address assigned. With this update, dhcrelay checks whether the interface has an address assigned prior to further processing of the received packet, and the relay agent no longer crashes in this scenario.
BZ#952126
Previously, when a DHCPv6 request from a DHCPv6 client came from a random port number, the DHCPv6 server sent the reply back to the source port of the message instead of sending it to UDP port 546, which is standard for IPv6. Consequently, the client got the reply on the incorrect port. The reply handling in the DHCPv6 server code has been fixed, and the server now sends replies to UDP port 546.
BZ#978420
Previously, the dhcpd daemon managed memory allocations incorrectly when manipulating objects via the Object Management API (OMAPI). As a consequence, several memory leaks were identified in dhcpd. With this update, memory allocation management has been fixed, and dhcpd no longer leaks memory in this scenario.
BZ#658855
Prior to this update, when the dhclient utility obtained a lease containing the "next-server" option, dhclient did not expose the option to the dhclient-script environment. Consequently, NetworkManager was not able to use the "next-server" option from the dhclient's lease. This bug has been fixed, dhclient now correctly exposes the "next-server" option and NetworkManager can use the option from the dhclient's lease.
BZ#919221
Previously, the dhcpd server was not able to properly handle parsing of a zone definition which contained two or more key statements. As a consequence, dhcpd returned a misleading error message about an internal inconsistency. The zone statement parsing code has been fixed; the error message reported by dhcpd is now more precise in this scenario, saying that there is a multiple key definition for the zone.
BZ#1001742
Previously, when the dhclient utility was running under IPv6 using multiple interfaces, only the last started instance was configured, while others lost connection after the lease-time had expired. Consequently, the last started instance of dhclient received all the DHCPv6 packets, while the other instances failed to communicate with the server. With this update, dhclient is now bound to a specified interface, and multiple instances of dhclient communicate correctly.
Users of dhcp are advised to upgrade to these updated packages, which fix these bugs.