Slide title In CAPITALS 50 pt Slide subtitle 32 pt Simple DNA draft-krishnan-dna-simple-03 Suresh Krishnan Greg Daley

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Background  Hosts require procedures to simply and reliably identify if they have moved to a different IP network to the one which they have been recently connected.  In order to detect change, router and neighbor discovery messages are used to collect reachability and configuration information.  This information is used to detect whether the existing router and address prefixes are likely to be present.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Characteristics of Simple DNA  Routers do not have to be modified to support this scheme.  Handle only the simplest and most likely use cases.  Work at least as quickly as standard neighbor discovery (RFC4861).  False positives are not acceptable. A host should not conclude that there is no link change when there is one  False negatives are acceptable. A host can conclude that there is a link change when there is none

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Applicability  Works well when hosts move between a known set of links  Does not provide much improvement when a host moves to a completely new link –Link detection is just as good as standard neighbor discovery (never slower) –Fast unicast RAs can make a difference here, but are not mandated

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Steps in Simple DNA A.Link-Layer Indication B.Probing C.Response gathering and assessment D.Optimistic DAD E.Verify other configuration (not in draft yet)

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Link layer indication  The host receives a link-layer indication that the medium has become available  This indication starts up the Simple DNA process  Host marks all current addresses as Optimistic  Host also marks all the default router neighbor cache entries as STALE

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Simple DNA table (SDAT)  The host maintains a table called the simple DNA table  The table contains at least the following information IPv6 Address Valid Lifetime PrefixLink local address of Router Link layer (MAC) address of router DUID for DHCPv6 assigned address

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Probing  The host sends an RS to the All-routers multicast address –The source address is a link local address –The address is in Optimistic state –The MAC address is inside a tentative option –Only 1 RS irrespective of the number of addresses the host possesses  The host sends one or more unicast NSs to routers in the SDAT  The RS and the NSs are sent in parallel –This is required to have a worst case scenario to be no worse than standard ND

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Response gathering and assesment  NA is received from a previously known router –Host verifies if both the link local ipv6 address AND the MAC address match –If they match, the host uses all the addresses related to the router in the SDAT (unless an RA is received)  RA is received from a previously known router (probed using NS) –Verify if the prefixes present in SDAT are present in the RA –If they are, continue to use them –If they are not, remove them from the SDAT  RA is received from a previously unknown router –Follow standard ND/SLAAC procedure for the prefixes present in the RA. –No modifications to the SDAT

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Optimistic DAD  After the addresses are confirmed as usable either by an NA or an RA –Verify whether the addresses are still unique  Use Optimistic DAD –Rejoin solicited node multicast addresses

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt © Ericsson AB 2008Simple DNA Pending work  Add an applicability section  Always use a link local address as the source of NS/RS  Confirm DHCP assigned addresses –DUID exists in Simple DNA table –Should we specify the procedure in this document or a different one?  Describe default router (re)selection procedure  Clarify some unclear text  Invent a new word than means valid