Why New L3 Protocol?
- Limited number of IPv4 address space
- Growing demand for Internet
- Issues in IPv4 Allocation Policy
How are we surviving with IPv4?
Still Internet can survive with some technical
implementations and Features of IPv4
- Network Address Translation (NAT) + Private IP
address block of Ipv4
* NAT allows ‘One to Many’ address allocations
* Private IP ranges - Proxy servers
* Allows Web access with private IP addresses - Name based virtual web hosting
- Network renumbering to reclaim large blocks of
address space allocated
Why Can’t go with v4
- 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
New IP Protocol - Design Goals?
- More address space
- Routing Efficiency
- Supports QoS
- Built in
– Security
– Mobility
– Extensibility
Types of IPv6 Addresses?
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.
what is the IPv6 Address Representation of this?
3ffe:3700:0200:00ff:0000:0000:0000:0001
This can be written as
–3ffe:3700:200:ff:0:0:0:1 or
–3ffe:3700:200:ff::1
Contract the following IPv6 address: 0000:0000:0000:0000:0000:a5b4:4381:1f25
::a5b4:4381:1f25
Fully expand the following IPv6 address: 0:0:d2f2:d66e:202f::
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
In IPv6 nodes (hosts and routers) use NDP to?
● 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
NDP – ICMP Packet Types
● Router Solicitation – ICMP type 133 ● Router Advertisement – ICMP type 134 ● Neighbor Solicitation – ICMP type 135 ● Neighbor Advertisement – ICMP type 136 ● Redirect – ICMP type 137
what is Neighbor Solicitation?
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)
what are steps in autoconfiguration?
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
what is the new field added in IPv6?
Flow label
why IPv6 Transition Technologies?
● 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
what are the IPv4 to IPv6 Basic Transition Mechanisms?
- Dual stack or dual IP layer architectures
- IPv6 over IPv4 tunneling
● ISATAP
● 6to4
● Teredo
● DS-lite - IPv6/ IPv4 Translations
● NAT64/DNS64
● NAT46
● NAT/PT
