Transcript PPT Version
zerouter BoF Problem Statement 19th Nov 2002 55th IETF - Atlanta, Georgia, USA [email protected] 1/7 Problem space • Main goal: self-configuring routers for un-administered networks NAT+RFC1918 IPv6 6to4 Ethernet 802.11 1394 SOHO Gateway Ethernet Powerline 2/7 L2 vs L3 • IP routing has advantages vs L2 bridging in the home/SOHO space: – – – – efficient forwarding works with non-802 addressed networks (1394, BT) Fragmentation and PMTU discovery Fail safe(r) • Commodity L2 bridges often lack 802.1d spanning tree • However: – IP subnet address assignment is manual – IP routing protocols currently need to be configured 3/7 Proposal • Develop zeroconf routing solutions that: – – – – automatically configure IP addressing automatically configure unicast IP forwarding automatically configure multicast IP forwarding detect and recover from inevitable addressing collisions 192.168.3.x 192.168.4.x 192.168.1.15 192.168.1.15 192.168.2.x 4/7 Unicast Approaches • Approaches for automatic unicast configuration: – decentralised subnet assignment • routers use a distributed protocol for choosing a subnet identifier from an available pool – multi-link subnets • multiple links are “bridged” together at the IP layer • only one IP subnet is necessary – ripple out explicit configuration • a centralised server allocates subnets/addresses for a network • or, allow sub-delegation to ripple out 5/7 Multicast • Bootstrap from working unicast addressing and routing • Zerouter protocols don’t introduce any new issues 6/7 Scope comments • In scope: – IPv4 and IPv6 solutions – solutions for 10s of links • Out of scope: – Development of new prefix delegation protocols – Auto-configuration of arbitrary router parameters (L2 media options, etc) – Auto-configuration of transit networks – Automatic configuration of services (e.g. DNS, SLP, etc) 7/7