ARP Mediation Updates Himanshu Shah Ciena Corp Andrew Dolganow & Neil Hart Alcatel/Lucent Eric Rosen Cisco Systems Giles Heron BT Vach Kompella Alcatel/Lucent Andy Malis Verizon Steven Wright AT&T Arun Vishwanathan Force10 Toby Smith NetApps Shane Amante Level 3

12/15/2015IETF-74 ARP Mediation Update 3/20092 Updates IPv6 portion is re-written Clarifying text added explaining why unicast traffic can not flow until ARP-mediation functions have completed. Responded to IP Directorate review comments Nits fixed, references updated

12/15/2015IETF-74 ARP Mediation Update 3/20093 IPv6 Link Layer IPv6 uses extensions of ICMP to exchange IPv6 and link address information with its neighbor IPv6 can have more than one IPv6 addresses for a given link IPv6 uses – – Inverse Neighbor Discovery (IND) for Point-to- point links such as FRL and ATM – Neighbor Discovery (ND) for multipoint links such as Ethernet

12/15/2015IETF-74 ARP Mediation Update 3/20094 Neighbor Discovery (ND) for Ethernet Same as ARP, IP DA is known, DMAC is being discovered An Ethernet based IPv6 sends ND solicitation message where – – SMAC set to sender’s MAC address, DMAC set to all-node mulitcast – IP header set to SRC IP and DST IP set to target IP – ICMP header target IP field set to target IP address – Optional Source Link address field – set to sender’s MAC address – Could contain multiple SRC IPv6 addr set The receiver responds with ND advertisement message where – SMAC set to responder’s MAC address, DMAC set to requester’s MAC – IP header set to SRC IP set to responder’s IP, DST IP set to requester’s IP – ICMP header target IP field of requester’s IP, ‘soliciter’ bit set – Optional Target Link address MUST be set to responder’s MAC address Unsolicited ND advertisement message can be set to notify newer info – SMAC set to advertiser’s MAC – DMAC set to all-node multicast MAC – IP header set to src IP with advertiser’s IP, dst IP set to all-node-multicast IP – ICMP header target IP field set to advertiser’s IP – ‘soliciter’ bit is reset, ‘override’ bit set

12/15/2015IETF-74 ARP Mediation Update 3/20095 Inverse Neighbor Discovery (IND) IND is typically used for point-to-point links such as ATM and FRL where SRC and DST Link information is known and seeking Destination IP address. IND solicitation has – IP header with SRC-IP set to sender’s IP and DST-IP set to all-node- multicast IP – ICMP fields have source and target link fields set to sender and target’s link and optional list of source IP addresses configured on that interface IND advertisement has – IP header with SRC-IP set to responder’s IP, DST-IP set to requester’s IP – ICMP fields have, source and target link fields set to responder and requester’s link address, target address list set to responder’s IP addresses configured on the interface

12/15/2015IETF-74 ARP Mediation Update 3/20096 Scheme Overview Use of ICMPv6 allows use of IP PW as compared to ARP packets that are non-IP PDU Let ICMPv6 packets flow across IP PW Let both PEs learn local/remote CE’s IP address information by snooping ICMPv6 packets from local AC and PW In case of disparate neighbor discovery scheme, provide appropriate termination/reciprocation functions (details follow).

12/15/2015IETF-74 ARP Mediation Update 3/20097 Both CEs are Ethernet CE1PE1PE2CE2 EthMPLSEth ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol ND-Adv Learn CE2’s Link & IP list ND-Adv Learn CE2’s IP addr list Src MAC=PE2 Src MAC=PE1 timeline

12/15/2015IETF-74 ARP Mediation Update 3/20098 Both CEs are Ethernet but uses ND- Adv only CE1PE1PE2CE2 EthMPLSEth ND-Adv Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Adv Learn CE2’s Link & IP list ND-Adv Learn CE2’s IP addr list Src MAC=PE2 Src MAC=PE1 timeline

12/15/2015IETF-74 ARP Mediation Update 3/20099 Both CEs are point-to-point CE1PE1PE2CE2 FRLMPLSFRL IND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list IND-Sol IND-Adv Learn CE2’s Link & IP list IND-Adv Learn CE2’s IP addr list timeline Src DLCI=PE2 Src DLCI=PE1

12/15/2015IETF-74 ARP Mediation Update 3/ CE1 is Eth, CE2 is FRL (option 1) CE1PE1PE2CE2 EthMPLSFRL ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol IND-Sol Learn CE2’s Link & IP list IND-Sol ND-Adv Learn CE2’s IP addr list timeline Src DLCI=PE2 Src MAC=PE1 IND-Adv Src DLCI=PE2 Since CE1’s IP Addr is known Two Actions

12/15/2015IETF-74 ARP Mediation Update 3/ CE1 is Eth, CE2 is FRL (option 1) CE1PE1PE2CE2 EthMPLSFRL ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol IND-Sol Learn CE2’s Link & IP list IND-Sol ND-Adv Learn CE2’s IP addr list and discard timeline Src DLCI=PE2 Src MAC=PE1 IND-Adv Src DLCI=PE2 Two Actions IND-Sol Learn CE2’s Link & IP list IND-Sol PE1 knows CE1’s IP addr so send IND-adv on PW and ND-adv on local AC

12/15/2015IETF-74 ARP Mediation Update 3/ CE1 is Eth, CE2 is FRL (option 2) CE1PE1PE2CE2 EthMPLSFRL ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list IND-Sol ND-Sol IND-Adv Learn CE2’s Link & IP list IND-Adv ND-Adv Learn CE2’s IP addr list timeline Src DLCI=PE2 Src MAC=PE1

12/15/2015IETF-74 ARP Mediation Update 3/ CE1 is Eth, CE2 is FRL (option 2) CE1PE1PE2CE2 EthMPLSFRL ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list IND-Sol ND-Sol IND-Adv Learn CE2’s Link & IP list IND-Adv ND-Adv Learn CE2’s IP addr list timeline Src DLCI=PE2 Src MAC=PE1 IND-Sol Learn CE2’s IP addr list IND-Sol Learn CE2’s IP addr list and discard

12/15/2015IETF-74 ARP Mediation Update 3/ Dual Stack Support When AC is configured to support dual stack CE, PE will advertise IPv4 and IPv6 Address Resolution capability using IPv4 and IPv6 address list TLV in Label Mapping message The common denominator address resolution mechanism is adopted based on capability exchange If remote CE does IPv4 or IPv6 only then local PE will engage in IPv4 or IPv6 based address resolution. When operating in reduced scope, operator is notified using event notification, alarms, etc At data plane level, IP version field is used to select appropriate link header.

12/15/2015IETF-74 ARP Mediation Update 3/ Conclusion We believe draft is ready for one more final call and then be sent for RFC approval The applicable IPv6 related changes from this draft will be ported to IPLS draft and will be submitted for final call