IPv4

Question 1

Why New L3 Protocol?

Answer 1

1. Limited number of IPv4 address space
2. Growing demand for Internet
3. Issues in IPv4 Allocation Policy

Question 2

How are we surviving with IPv4?

Answer 2

Still Internet can survive with some technical
implementations and Features of IPv4

1. Network Address Translation (NAT) + Private IP
   address block of Ipv4
   * NAT allows ‘One to Many’ address allocations
   * Private IP ranges
2. Proxy servers
   * Allows Web access with private IP addresses
3. Name based virtual web hosting
4. Network renumbering to reclaim large blocks of
   address space allocated

Question 3

Why Can’t go with v4

Answer 3

1. It is too OLD to cater New Requirements

• Mobility
• Security
• Multi-casting
  2. Issues with NATing
  3. Routing table issues
  4. High demand for IP address
  5. Always live devices needs real IPs

Question 4

New IP Protocol - Design Goals?

Answer 4

1. More address space
2. Routing Efficiency
3. Supports QoS
4. Built in
   – Security
   – Mobility
   – Extensibility

Question 5

Types of IPv6 Addresses?

Answer 5

Unicast
– packets delivered to the (one) addressed
interface
• Multicast
– Packets delivered to all interfaces with that
address
• Anycast:
-Packets delivered to one (the “nearest”) of the interfaces identified by that address.

Question 6

what is the IPv6 Address Representation of this?

3ffe:3700:0200:00ff:0000:0000:0000:0001

Answer 6

This can be written as
–3ffe:3700:200:ff:0:0:0:1 or
–3ffe:3700:200:ff::1

Question 7

Contract the following IPv6 address: 0000:0000:0000:0000:0000:a5b4:4381:1f25

Answer 7

::a5b4:4381:1f25

Question 8

Fully expand the following IPv6 address: 0:0:d2f2:d66e:202f::

Answer 8

0000:0000:d2f2:d66e:202f:0000:0000:0000

Add leading zeros to every 16-bet set less than 4 characters
Expand :: into 16-bit sets of zeros until you have eight 16-bit sets total

Question 9

In IPv6 nodes (hosts and routers) use NDP to?

Answer 9

● Address Autoconfiguration
● Router discovery
– locate routers residing on attached links
● Parameter Discovery
– find link parameters (e.g., MTU)
● Address resolution
– link-layer addresses for neighbors
● Duplicate Address Detection

Question 10

NDP – ICMP Packet Types

Answer 10

● Router Solicitation – ICMP type 133
● Router Advertisement – ICMP type 134
● Neighbor Solicitation – ICMP type 135
● Neighbor Advertisement – ICMP type 136
● Redirect – ICMP type 137

Question 11

what is Neighbor Solicitation?

Answer 11

Sent by a node
● to determine the link-layer address of a neighbor,
● to verify that a neighbor is still reachable via a
cached link-layer address.
● used for Duplicate Address Detection (DAD)

Question 12

what are steps in autoconfiguration?

Answer 12

Host starts
– Assigns itself a link local address
       • Uses prefix FE80:0:0:0
       • Uses EUI-64 address
– Configures interface to receive
addresses
      • FF02::1(All Nodes Multicast Address)

• Verify the uniqueness of the tentative link-
local address

– a Neighbor Solicitation message is sent
with the Target Address field that is set
to the tentative link-local address - DAD

Question 13

what is the new field added in IPv6?

Answer 13

Flow label

Question 14

why IPv6 Transition Technologies?

Answer 14

● To facilitate the transitioning of the Internet from its
IPv4 infrastructure to IPv6
● allows hosts only connected with either IPv4 or IPv6
to access resources only available using the other
protocol

Question 15

what are the IPv4 to IPv6 Basic Transition Mechanisms?

Answer 15

1. Dual stack or dual IP layer architectures
2. IPv6 over IPv4 tunneling
   ● ISATAP
   ● 6to4
   ● Teredo
   ● DS-lite
3. IPv6/ IPv4 Translations
   ● NAT64/DNS64
   ● NAT46
   ● NAT/PT