1. 1/7 zerouter BoF Problem Statement 19 th Nov 2002 55th IETF - Atlanta, Georgia, USA aidan.williams@motorola.com

2. 2/7 Problem space Main goal: self-configuring routers for un-administered networks Powerline 1394 802.11 Ethernet SOHO Gateway NAT+RFC1918 IPv6 6to4

3. 3/7 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

4. 4/7 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 192.168.1.15 192.168.2.x 192.168.3.x 192.168.4.x

5. 5/7 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

6. 6/7 Multicast Bootstrap from working unicast addressing and routing Zerouter protocols don’t introduce any new issues

7. 7/7 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)