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IPv6 Notes
Question | Answer |
---|---|
TCP/IPv6 Application Layer Changes | DHCPv6 replaces DHCPv4 |
TCP/IPv6 Transport Layer Changes | TCPv6 & UDPv6 replace TCP & UDP |
TCP/IPv6 Internet Layer Changes | IPv6 & ICMPv6 replace IPv4 & ICMP |
TCP/IPv6 Link Layer Changes | Neighbhor Discovery (ND) supersedes and replaces ARP |
IPv6 Addressing | 128 bit Address (16 octets/bytes) written in Hex format over 8 fields separated by colons |
IPv6 Abbreviation Rules | 1) Leading zeros are optional 2) Represent one or more consecutive quartets of all hex 0's with a double colon |
IPv6 Conventions | IPv4 = Network.Host IPv6 = Prefix.Interface_ID -Prefix = "where you are connected to" -Interface ID = "who you are" |
IPv6 General Address Format | Global_Routing_Prefix.Subnet_ID.Interface_ID Global = n bits Subnet = m bits Interface = 128-n-m bits |
IPv6 Address Allocation Hierarchy | 1) IANA 2) RIR's 3) ISP's/LIR's 4) Site Address 5) Subnet |
IANA | Internet Assigned Numbers Authority |
Name the 5 RIR's | AFRINIC ARIN APNIC LACNIC RIPE |
Assigned "Unspecified" Prefix | ::/128 |
Assigned "Loopback" Prefix | ::1/128 |
Assigned "Multicast" Prefix | FF00::/8 |
Assigned "Link-Local Unicast" Prefix | F280::/10 |
Assigned "Unique Local Unicast" Prefix | FC00::/7 |
Assigned "Global Unicast" Prefix | 2000::/3 |
IPv4 adds in a new function named... | Anycast = "One to Nearest" -Address corresponds to a set of computers that share a common address prefix--delivered on shortest path to nearest one. NO concept of broadcast now. Multicast is used instead. |
Describe IPv6 Header Structure | -Version -Traffic Class -Flow Label -Payload Length -Next Header -Hop Limit -Source Address -Destination Address |
IPv6 Fields & Lengths (versus IPv4) | IPv6 -8 Fields -Fixed 40 bytes length IPv4 -13 Fields -Varies between 20 to 60 bytes |
What fields were removed from IP header in IPv6? | -Header Checksum -Header Length -Identification -Flags -Fragment Offset |
What fields were renamed/modified? | Type of Service = Traffic Class Protocol Type = Next Header Total Length = Payload Length TTL = Hop Limit |
What field is brand new to IPv6? | Flow Label |
What extension headers can be added to IPv6? | -Hop by Hop Options -Destination Options -Routing Header -Fragment Header -Authentication Header -ESP Header -Upper Layer Header |
ICMPv6 | Commonly used to send error messages -Neighbor Discovery Protocol -Path MTU Discovery -Multicast Listener Discovery (MLD) Protocol |
Neighbor Discovery (ND) replaces what protocols? | -ARP -ICMP Router Discovery -ICMP Redirect ND determines L2 addresses of nodes on the same link, finds neighboring routers that can forward packets/are reachable, and detects changed link layer addresses. |
ND uses what 5 ICMPv6 messages | -Router Solicitation (RS) -Router Advertisement (RA) -Neighbor Solicitation -Neighbor Advertisement -Redirect |
How can IPv6 interfaces be assigned? | -Manually Configured -Assigned via DHCP (Stateful) -Stateless Auto-Configuration -Auto-generated Pseudo-random Number |
How does Stateless Autoconfiguration work? | A 64-bit EUI-64 is created by expanding the 48-bit MAC address with a Link Local prefix (FE80::/64). Expansion done by inserting 2 bytes (Hex FFFE) between OUI and the seventh bit to 1. |
What mechanisms exist for transitioning/coexisting with IPv4? | --Dual-Stack --Tunneling (Encapsulation) --Translation (Uses NAT-PT) |