DHCPv4 Bulk Leasequery

Abstract

The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) Leasequery protocol allows a requestor to request information about DHCPv4 bindings. This protocol is limited to queries for individual bindings. In some situations, individual binding queries may not be efficient or even possible. This document extends the DHCPv4 Leasequery protocol to allow for bulk transfer of DHCPv4 address binding data via TCP. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6926.

Privacy Considerations for DHCP

“…Furthermore, the attackers may use the DHCP bulk leasequery [RFC6926] mechanism to obtain bulk information about DHCP bindings, even without knowing the target bindings.…”

Active DHCPv4 Lease Query

“…Requesting and receiving the information about all or some of the existing DHCPv4 binding information in an efficient manner, as defined by [RFC6926]. o "blocked TCP connection" A TCP connection is considered blocked if the underlying TCP transport will not accept new messages to be sent without blocking the thread that is attempting to send the message.…”

“…The Active Leasequery mechanism is modeled on the existing individual Leasequery protocol in [RFC4388] as well as related work on DHCPv4 Bulk Leasequery [RFC6926]; most differences arise from the long-term nature of the TCP [RFC7414] connection required for Active Leasequery. In addition, a DHCPv4 server that supports Active Leasequery must support Bulk Leasequery [RFC6926] as well.…”

“…The DHCPv4 Bulk Leasequery [RFC6926] capability can be used to recover useful information from a DHCPv4 server when some external entity starts up. This entity could be one that is directly involved in the DHCPv4 client-server transactions (e.g., a relay agent), or it could be an external process that needs information present in the DHCPv4 server's lease state database.…”

“…This document updates DHCPv4 Bulk Leasequery [RFC6926] in that it specifies the DHCPv4 server must close the TCP connection if it receives a DHCPv4 message that is not allowed over the TCP connection (for example, DHCPDISCOVER, DHCPLEASEQUERY). See Section 8.1.1.…”