IPv6

Question 1

Length of IPv4 address

Answer 1

32 bit

Question 2

Length of an IPv6 address

Answer 2

128 bit

Question 3

IPv6 improvements

Answer 3

128 bit
IPsec
aggregation (smaller routing table)
doesn’t need DHCP

Question 4

what does IPv6 use to communicate on a local network

Answer 4

• link-local addressing (unicast)
• (like IPv4 APIPA)
• every address starts with fe80::/10
  fe80: 0000:0000:0000
• 2nd 64 bits are generated randomly, on older systems like XP and server 2003, uses the MAC address to create called Extended Unique Identifier, 64-bit (EUI-64)

Question 5

Parts of IPv6

Answer 5

• 8 Groups called quartet or hextet (between 0000 and ffff) separated by colons
• first 64 bits are the network prefix (for routing)
  
  • 48 bit Global routing prefix (from upstream router)
  • 16 bit subnet ID
• 2nd 64 bits are user address, called interface ID

Question 6

rules to shorten an IPv6 address

Answer 6

• leading zeroes can be dropped from each quartet (so 00cf becomes cf, 0000 becomes 0)
• use :: for groups of zeroes (only once)

Question 7

multicast

Answer 7

• a set of reserved addresses designed to go only to certain systems
• every system see’s the frame, but only computers set up to process the frame process it

Question 8

IPv6 multicast addresses

Answer 8

ff02: :1 - all nodes address
ff02: :2 - all routers address
ff02: :1:ffxx:xxxx - solicited node address

Question 9

Root hints

Answer 9

file of the IP addresses of the root DNS servers of the internet

Question 10

anycast

Answer 10

• gives a number of computers the same IP address
• routers use BGP to determine which computer in the cluster is closest
• sends packets only to closest computer

Question 11

prefix delegation

Answer 11

tells the router to go upstream to the ISP and get a prefix to hand out
any changes upstream will pass downstream

Question 12

what do computers on IPv6 need to access the internet

Answer 12

global unicast address

Question 13

no-default routers

Answer 13

top tier routers, can’t have a default route

Question 14

aggregation

Answer 14

every router underneath one router always uses a subset of that router’s existing routes

Question 15

NDP

Answer 15

Neighbor Discovery Protocol

• has 5 packet types:
• neighbor solicitation - mulicast packet searching for other computers on its broadcast domain
• neighbor advertisement - response to solicitation
• router solicitation - request for a router advertisement (only happens when a computer hasn’t heard from the router recently)
• router advertisement - sends out addresssing information to all LAN hosts
• redirect

Question 16

DHCPv6

Answer 16

• used if you dont want addressing from upstream
• stateful mode - passes out info like v4 DHCP
• stateless mode - uses router advertisements

Question 17

4to6

Answer 17

IPv4-to-IPv6 tunnel

- encapsulate IPv4 traffic into an IPv6 tunnel, to get to an IPv6 capable router

Question 18

6in4

Answer 18

IPv6-in-IPv4

- can go through IPv4 NAT

Question 19

Teredo

Answer 19

Nat-traversal IPv6 tunneling protocol for windows

• start with 2001:0000:/32
• Miredo is open source for Unix/Linux

Question 20

ISATAP

Answer 20

Intra-Site Automatic Tunnel Addressing Protocol

- works in an IPv4 network by adding the IPv4 address to an IPv6 prefix

Question 21

Tunnel Brokers

Answer 21

create the actual tunnel and offer a custom-made enpoint client
- take advantage of one of two protocols:
TSP - Tunnel Setup Protocol
TIC - Tunnel Information and Control Protocol

Question 22

Overlay Tunnels

Answer 22

enables two IPv6 networks to connect over existing IPv4 infrastructure

Question 23

NAT64

Answer 23

transition mechanism that embeds IPv4 packets into IPv6

Question 24

What kind of DNS records to IPv6 addresses use

Answer 24

AAAA

Question 25

Is NAT needed with IPv6

Answer 25

No, the address space is so large that rationing routable addresses is unecessary

Question 26

What is the /16 prefix for all 6to4 addresses?

Answer 26

2002