Skip to main content

Enterprise Multihoming using Provider-Assigned Addresses without Network Prefix Translation: Requirements and Solution

Document Type Replaced Internet-Draft (candidate for rtgwg WG)
Expired & archived
Authors Fred Baker , Chris Bowers , Jen Linkova
Last updated 2017-02-21 (Latest revision 2016-10-31)
Replaced by RFC 8678
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Stream WG state Call For Adoption By WG Issued
Document shepherd (None)
IESG IESG state Replaced by draft-ietf-rtgwg-enterprise-pa-multihoming
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


Connecting an enterprise site to multiple ISPs using provider- assigned addresses is difficult without the use of some form of Network Address Translation (NAT). Much has been written on this topic over the last 10 to 15 years, but it still remains a problem without a clearly defined or widely implemented solution. Any multihoming solution without NAT requires hosts at the site to have addresses from each ISP and to select the egress ISP by selecting a source address for outgoing packets. It also requires routers at the site to take into account those source addresses when forwarding packets out towards the ISPs. This document attempts to define a complete solution to this problem. It covers the behavior of routers to forward traffic taking into account source address, and it covers the behavior of host to select appropriate source addresses. It also covers any possible role that routers might play in providing information to hosts to help them select appropriate source addresses. In the process of exploring potential solutions, this documents also makes explicit requirements for how the solution would be expected to behave from the perspective of an enterprise site network administrator .


Fred Baker
Chris Bowers
Jen Linkova

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)