Deterministic Fast Router Advertisement Configuration

Update

draft-daley-dna-det-fastra-01.txt

Presenter: Greg Daley

Status of draft

• Feedback from 00 draft– Preferred simpler solution if available.– Issues captured and tracked (not all resolved)

Feedback from 00 draft by Jari Arkko and SooHong (Daniel) Park

• Changes incorporated into -01– No Host interaction with DetFRA options– Simplification of delay calculation (Impl).

Why Deterministic Fast RA?

• Getting RAs fast is part of DNA goals• Existing RS response proposals didn’t

allow automated Fastest Router conf– Rely on only one router, or manual config

• Deterministic Fast RA provides a negotiated ordering amongst responding routers– Automated– Works with arbitrary router topologies

Implementation

• Router function implemented in RADVD– Early alpha, a few days to implement (< week)– Tested under Linux.

• Uses ICMPv6 Router-to-Router messages.– Exchanged messages modify router ranking

• Router responses at agreed fixed delay – Requires Router Solicitations (link hints?)

• No Multicast FastRAs yet.

Coding Issues (Ranking)

• RankScore calculation straightforward

• Ranking possible as list– update on RtR receive.– Care needed to make checks simple, fast.

• Original timing calculations cumbersome– Sum of preceding router’s Separation values– Suggest FixDelay= (Rank – 1) * SepFastest

Coding Issues (Messages)

• Router-to-Router (RtR) state machine & DetFastRA messaging separate tasks– separately or together??

• Router-to-Router Messages– controls change advertisement– provides transport

• LinkID reuses RtR state machine.

• No SEND authorization on RtR yet

Differences in Draft-01

• Removes:– All host facing DetFastRA messages removed

• Changes:– Tidied up RtR state timers– Change delay calculation to (Rank-1)*Sepfastest

– Suggested new router-to-router multicast group

Action Items (1 of 2)

• Get feedback from WG– Usefulness– Complexity– Validity of Router-to-Router– Document contents (RtR method?)

• Follow up existing issues list

• Make code available (BSD license - radvd)

Action Items (2 of 2)

• Router Ranking Convergence testing– Largely predictable

• Testing with packet loss– Effects on convergence– Effects on DNA timing

• SEND Router authorization (further out)

• Scalability simulation/calibration– Determine maximum effective ranks.

References:

• Issues list and draft diffs:– http://ctieware.eng.monash.edu.au/twiki/bin/

view/DNA/DetFastRA

• Related drafts– draft-daley-dna-det-fastra-01.txt– draft-mkhalil-ipv6-fastra-05.txt– draft-pentland-mobileip-linkid-02.txt– draft-ietf-ipv6-2461bis-01.txt– RFC 2461