DHCP Options for Configuring Tenant Identifier and Multicast Addresses in Overlay Networks Behcet Sarikaya Frank Xia Shi Fan 1 draft-sarikaya-nvo3-dhc-vxlan-multicast-02

PROBLEM STATEMENT IP Multicast mechanism in the overlay network is required How to deliver ARP to all nodes? How to deliver IPv6 ND messages to all nodes? NVE needs to get IPv4/IPv6 multicast address Network Virtualization Edge node needs to know the tenant identifier for VM NVE needs to get tenant id or VXLAN Network Identifier The draft defines DHCP options for these two 2

Address Resolution Scaling RFC 6820 examines address resolution in DC In IPv4, to determine the link-layer address of a given a node broadcasts an ARP Request How to deliver broadcast (large amount of broad casts) in a DC with large number of hosts? In IPv6, when querying for a target IP address, ND maps the target address into an IPv6 Solicited Node multicast address Using multicast scales better because frames can be sent only to segments with listeners Most nodes will filter out the (unwanted) multicast query via filters installed in NICs or at the vSwitch 3

DHCPv6/v4 Options Page 4 - VNI Option - VXLAN Multicast Address Option

Page 5 NVE sends DHCPDISCOVER message NVE adds parameter request list option with VXLAN Network Identifier NVE adds VXLAN Multicast Address option Server sends DHCPOFFER message NVE sends DHCPv6 Solicit message NVE adds Option Request Option with VNI option (OPTION_VNI) NVE adds Multicast Address Option (OPTION_MA) Server sends DHCPv6 Advertise message DHCPv4 DHCPv6 Call Flow NVE gets values from DHCPv4/v6 Server DHCPv4/v6 server must know VNI value before assigning multicast addresses How DHCPv4/v6 server gets VNI value is out of scope

Next Steps WG draft? 6