DHC A. Kostur
Internet-Draft Incognito
Updates: 3074 (if approved) August 28, 2012
Intended status: Standards Track
Expires: February 27, 2013
DHC Load Balancing Algorithm for DHCPv6
draft-kostur-dhc-loadbv6-00
Abstract
This document proposes a method of algorithmic load balancing for
DHCPv6 traffic. It enables multiple, cooperating servers to decide
which one should service a client, without exchanging any information
beyond initial configuration. The server selection is based on the
servers hashing client DHCP Unique Identifiers (DUIDs) when multiple
IPv6 Dynamic Host Configuration Protocol (DHCPv6) servers are
available to service DHCPv6 clients. The proposed technique provides
for efficient server selection when multiple DHCPv6 servers offer
services on a network without requiring any changes to existing
DHCPv6 clients. The same method is proposed to select the target
server of a DHCPv6 relay.
Status of This Memo
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This Internet-Draft will expire on February 27, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Internet-Draft DHC Load Balancing Algorithm for DHCPv6 August 2012
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Background and External Requirements . . . . . . . . . . . . . 2
3. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.1. Selecting the STID . . . . . . . . . . . . . . . . . . . . 2
3.2. Replacing the secs field . . . . . . . . . . . . . . . . . 3
4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
6. Security Considerations . . . . . . . . . . . . . . . . . . . 3
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 3
7.1. Normative References . . . . . . . . . . . . . . . . . . . 3
7.2. Informative References . . . . . . . . . . . . . . . . . . 3
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 3
1. Introduction
This protocol is intended to extend the algorithm described in RFC
3074 [RFC3074] to apply to DHCPv6 traffic. Most of the terminology
and procedures are identical to the ones specified in RFC 3074.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. Background and External Requirements
The requirements for DHCPv6 are substantially the same as for DHCPv4,
replacing DHCPDISCOVER with SOLICIT, DHCPREQUEST with REQUEST,
CONFIRM, RENEW, or REBIND (as appropriate), etc.
3. Operation
A DHCPv6 server performing this load balancing will operate in
substantially the same manner as if it were a DHCPv4 server load
balancing an incoming DHCPv4/BOOTP packet with the following two
differences.
3.1. Selecting the STID
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Internet-Draft DHC Load Balancing Algorithm for DHCPv6 August 2012
DHCPv6 servers MUST use the client's DUID as the STID. At most the
first 16 bytes of the DUID are used. Of the 4 DUID types that
currently exist, only a DUID-UUID [RFC6355] is guaranteed to exceed
16 bytes. The variability of the first 14 bytes of the UUID should
be sufficient to allow for the hashing function to perform
adequately.
3.2. Replacing the secs field
A DHCPv6 server providing the capability of Delayed Service SHOULD
use the value in the OPTION_ELAPSED_TIME wherever RFC 3074 makes
reference to the secs field.
4. Acknowledgements
Thanks to Bernie Volz, Steve Gonczi, Ted Lemon, and Rob Stevens as
this document heavily borrows from their previous work on RFC 3074.
5. IANA Considerations
This memo includes no request to IANA.
6. Security Considerations
This proposal in and by itself provides no security, nor does it
impact existing security. Servers using this algorithm are
responsible for ensuring that if the contents of the HBA are
transmitted over the network as part of the process of configuring
any server, that message be secured against tampering, since
tampering with the HBA could result in denial of service for some or
all clients.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3074] Volz, B., Gonczi, S., Lemon, T., and R. Stevens, "DHC Load
Balancing Algorithm", RFC 3074, February 2001.
7.2. Informative References
[RFC6355] Narten, T. and J. Johnson, "Definition of the UUID-Based
DHCPv6 Unique Identifier (DUID-UUID)", RFC 6355, August
2011.
Author's Address
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Internet-Draft DHC Load Balancing Algorithm for DHCPv6 August 2012
Andre Kostur
Incognito Software Inc.
#500 - 375 Water St.
Vancouver, BC
CA
Phone: +1 604 678 2864
Email: akostur@incognito.com
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