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

IETF-74 ARP Mediation Update 3/2009 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 8/28/2018 IETF-74 ARP Mediation Update 3/2009

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 8/28/2018 IETF-74 ARP Mediation Update 3/2009

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 8/28/2018 IETF-74 ARP Mediation Update 3/2009

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 8/28/2018 IETF-74 ARP Mediation Update 3/2009

IETF-74 ARP Mediation Update 3/2009 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). 8/28/2018 IETF-74 ARP Mediation Update 3/2009

IETF-74 ARP Mediation Update 3/2009 Both CEs are Ethernet Eth MPLS Eth CE1 PE1 PE2 CE2 timeline ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol ND-Sol Src MAC=PE2 Learn CE2’s Link & IP list ND-Adv Learn CE2’s IP addr list ND-Adv ND-Adv Src MAC=PE1 8/28/2018 IETF-74 ARP Mediation Update 3/2009

Both CEs are Ethernet but uses ND-Adv only MPLS Eth CE1 PE1 PE2 CE2 timeline ND-Adv Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Adv ND-Adv Src MAC=PE2 Learn CE2’s Link & IP list ND-Adv Learn CE2’s IP addr list ND-Adv ND-Adv Src MAC=PE1 8/28/2018 IETF-74 ARP Mediation Update 3/2009

Both CEs are point-to-point FRL MPLS FRL timeline CE1 PE1 PE2 CE2 IND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list IND-Sol IND-Sol Src DLCI=PE2 Learn CE2’s Link & IP list IND-Adv Learn CE2’s IP addr list IND-Adv IND-Adv Src DLCI=PE1 8/28/2018 IETF-74 ARP Mediation Update 3/2009

CE1 is Eth, CE2 is FRL (option 1) MPLS FRL timeline CE1 PE1 PE2 CE2 ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol ND-Sol Src DLCI=PE2 Learn CE2’s Link & IP list IND-Sol Learn CE2’s IP addr list IND-Sol Since CE1’s IP Addr is known IND-Adv IND-Adv ND-Adv Src DLCI=PE2 Src MAC=PE1 Two Actions 8/28/2018 IETF-74 ARP Mediation Update 3/2009

CE1 is Eth, CE2 is FRL (option 1) MPLS FRL timeline CE1 PE1 PE2 CE2 Learn CE2’s Link & IP list IND-Sol Learn CE2’s IP addr list and discard IND-Sol ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol ND-Sol Src DLCI=PE2 Learn CE2’s Link & IP list PE1 knows CE1’s IP addr so send IND-adv on PW and ND-adv on local AC IND-Sol IND-Sol IND-Adv IND-Adv ND-Adv Src MAC=PE1 Src DLCI=PE2 Two Actions 8/28/2018 IETF-74 ARP Mediation Update 3/2009 11

CE1 is Eth, CE2 is FRL (option 2) MPLS FRL timeline CE1 PE1 PE2 CE2 ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol IND-Sol Src DLCI=PE2 Learn CE2’s Link & IP list IND-Adv Learn CE2’s IP addr list IND-Adv ND-Adv Src MAC=PE1 8/28/2018 IETF-74 ARP Mediation Update 3/2009

CE1 is Eth, CE2 is FRL (option 2) MPLS FRL timeline CE1 PE1 PE2 CE2 IND-Sol IND-Sol Learn CE2’s IP addr list Learn CE2’s IP addr list and discard ND-Sol Learn CE1’s Link Addr & IP Learn CE1’s IP addr list ND-Sol IND-Sol Src DLCI=PE2 Learn CE2’s Link & IP list Learn CE2’s IP addr list IND-Adv IND-Adv ND-Adv Src MAC=PE1 8/28/2018 IETF-74 ARP Mediation Update 3/2009 13

IETF-74 ARP Mediation Update 3/2009 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 8/28/2018 IETF-74 ARP Mediation Update 3/2009