IPv6 통신방식 (Unicast, Multicast, Anycast)

1. Unicast

• 1:1 communication
• Similar with ipv4 unicast

Types of IPv6 UNICAST Addresses

Type	Use	Begins with
Global Unicast Address	Public IP, internet routing	2000::/3
Link-Local Address	Automatically assigned, Within the same link(Ethernet)	fe80::/64
Unique Local Address (ULA)	Private IP, Specific local region	fc00::/7

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2. Multicast

• 1 to Multiple Receivers within a Specific Group
• Similar with ipv4 Broad cast

2type of ipv6 multicast address
Well-known multicast addresses - used in DHCPv6
Solicited-node multicast addresses

Types of IPv6 MULTICAST Addresses

Solicited Node Multicast	All node multicast	All router multicast
Neighbor Discovery process in an Ethernet	Group includes all IPv6 host and router	Group includes all ipv6 router
Used in Auto configuration DAD(Duplicate Address Detection)	FF02::1	FF02::2
Address format: FF02::1:FF(112bit) + lower 24 bits of the IPv6(24bit)
IPv6 addr 2001:1:1:1::1234:5678 → Solicited node multicast addr FF02::1:FF34:5678

Reserved Multicast Addresses

Address and Scope of IPv6 Groups

출처-한국인터넷정보센터

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3. Anycast

• Sender to nearest Receiver
• DNS, CDN, IPv6 Routers's Anicast address
• Anycast is similar to multicast, but only one device responds