IPv6 features include:
- Supports source and destination addresses that are 128 bits (16 bytes) long.
- Requires IPSec support.
- Uses Flow Label field to identify packet flow for QoS handling by router.
- Allows the host to send fragments packets but not routers.
- Doesn’t include a checksum in the header.
- Uses a link-local scope all-nodes multicast address.
- Does not require manual configuration or DHCP.
- Uses host address (AAAA) resource records in DNS to map host names to IPv6 addresses.
- Uses pointer (PTR) resource records in the IP6.ARPA DNS domain to map IPv6 addresses to host names.
- Supports a 1280-byte packet size (without fragmentation).
- Moves optional data to IPv6 extension headers.
- Uses Multicast Neighbor Solicitation messages to resolve IP addresses to link-layer addresses.
- Uses Multicast Listener Discovery (MLD) messages to manage membership in local subnet groups.
- Uses ICMPv6 Router Solicitation and Router Advertisement messages to determine the IP address of the best default gateway.
This YouTube video by makkyosky provides an entry-level overview of why we need IPv6.