1. Network Layer Protocols: ARP, IPv4, ICMP, IPv6 and ICMPv6

2. Internet Group Management Protocol Reversed ARP
Figure Protocols at network layer
Internet Group Management Protocol
Multicasting
Reversed ARP
Obsolete
Internet Control Message Protocol
Provides error control and messaging capabilities in unicasting
Address Resolution Protocol
Find MAC address
of next-hop host
Internet Protocol:
Provides connectionless, best-effort delivery routing of datagrams,
is not concerned with the content of the datagrams;
looks for a way to move the datagrams to their destination

3. ARP
Mapping
Packet Format
Encapsulation
Operation

4. Figure ARP operation

5. Figure ARP packet

6. Figure 20.4 Encapsulation of ARP packet

7. Figure 20.5 Four cases using ARP

8. An ARP request is broadcast; an ARP reply is unicast.
Note:
An ARP request is broadcast; an ARP reply is unicast.

9. Example 1
A host with IP address and physical address B has a packet to send to another host with IP address and physical address A46EF45983AB. The two hosts are on the same Ethernet network. Show the ARP request and reply packets encapsulated in Ethernet frames.
Solution
Figure 20.6 shows the ARP request and reply packets. Note that the ARP data field in this case is 28 bytes, and that the individual addresses do not fit in the 4-byte boundary. That is why we do not show the regular 4-byte boundaries for these addresses. Note that we use hexadecimal for every field except the IP addresses.

10. Figure Example 1

11. 20.2 IP Datagram Fragmentation
IP provides an unreliable service (i.e., best effort delivery). This means that the network makes no guarantees about the packets proper arrival and any of the following may occur:
data corruption
out-of-order delivery (Given packet A is sent before packet B, packet B can arrive before packet A.)
duplicate arrival
lost or dropped/discarded packages
IPv4, however, does provide some reliability in terms of integrity of the packet, ensuring the IP packet's header is error-free through the use of a checksum. This has the side-effect of discarding packets with bad headers on the spot, and with no required notification to either end (though an ICMP message may be sent). IPv6, on the other hand, has abandoned the use of IP header checksums for the benefit of rapid forwarding through routing elements in the network.
To address any of these reliability issues, an upper layer protocol must handle it. For example, to ensure in-order delivery the upper layer may have to cache data until it can be passed up in order.
If the upper layer protocol does not self-police its own packet size by first examining the maximum transmission unit (MTU) size, and sends the IP layer too much data, IP is forced to fragment the original datagram into smaller fragments for transmission. IP does provide re-ordering of any fragments that arrive out of order by using the fragmentation flags and offset[1]. Transmission Control Protocol (TCP) is a good example of a protocol that will adjust its segment size to be smaller than the MTU. User Datagram Protocol (UDP) and Internet Control Message Protocol (ICMP) are examples of protocols that disregard MTU size thereby forcing IP to fragment oversized datagrams.[2]
The primary reason for the lack of reliability is to reduce the complexity of routers. While this does give routers carte blanche to do as they please with packets, anything less than best effort yields a poor experience for the end user. So, even though no guarantees are made, the better the effort made by the network, the better the experience for the user. Most protocols are built around the idea that error checking is best done at each end of the communication line,

12. Figure IP datagram

13. IP Datagram Fields VERS - Version number
HLEN - Header length, in 32-bit words
Type of Service - How the datagram should be handled
Total Length - Total length, header + data
Identification, Flags, Frag. Offset - Provides fragmentation of datagrams to allow differing MTU's in the Internetwork
TTL - Time-To-Live
Protocol - The upper-layer (Layer 4) protocol sending and receiving the datagram
Header Checksum - An integrity check on the header
Source IP Address and Destination IP Address - 32-bit IP addresses
IP Options - Network testing, debugging, security, and other options
Data - Data

14. Figure Multiplexing

15. Figure 20.9 Example of checksum calculation

16. Figure 20.11 Fragmentation example

17. Figure MTU

18. 20.3 ICMP Types of ICMP Messages
IP gives unreliable and connectionless datagram delivery.
So it gives best-effort delivery service.
Efficient use of network resources.
No error control/reporting.
No messaging capability.
ICMP = Internet Control Message Protocol
Types of ICMP Messages

19. Figure 20.12 ICMP encapsulation

20. ICMP always reports error messages to the original source.
Note:
ICMP always reports error messages to the original source.

21. Figure 20.13 Error-reporting messages
Packet discarded
router/host gets
Datagram with 0 TTL,
or fragments arrive late.
Packet discarded,
router/host cannot
deliver datagram.
Packet sent to
wrong router.
Packet discarded,
router/host is
congested. Added
Flow control to IP.
Packet discarded,
router/host gets
ambiguous datagram.

22. There is no flow control or congestion control mechanism in IP.
Note:
There is no flow control or congestion control mechanism in IP.

23. Figure 20.14 Query messages Identify network communication
problems between
systems (host or routers)
Get mask to identify
network or subnetwork
part of IP address.
Get round-trip time,
Synchronize clocks.
Get information of
alive and functioning
routers.

24. 20.4 IPv6 IPv6 Addresses Categories of Addresses IPv6 Packet Format
Fragmentation
ICMPv6
Transition

25. (2) Population numbers are based on data from the US Census Bureau .
WORLD INTERNET USAGE AND POPULATION STATISTICS
World Regions
Population ( 2008 Est.)
Internet Users Dec/31, 2000
Internet Usage, Latest Data
% Population (Penetration)
Usage % of World
Usage Growth
Africa
955,206,348
4,514,400
51,065,630
5.3 %
3.5 %
1,031.2 %
Asia
3,776,181,949
114,304,000
578,538,257
15.3 %
39.5 %
406.1 %
Europe
800,401,065
105,096,093
384,633,765
48.1 %
26.3 %
266.0 %
Middle East
197,090,443
3,284,800
41,939,200
21.3 %
2.9 %
1,176.8 %
North America
337,167,248
108,096,800
248,241,969
73.6 %
17.0 %
129.6 %
Latin America/Caribbean
576,091,673
18,068,919
139,009,209
24.1 %
9.5 %
669.3 %
Oceania / Australia
33,981,562
7,620,480
20,204,331
59.5 %
1.4 %
165.1 %
WORLD TOTAL
6,676,120,288
360,985,492
1,463,632,361
21.9 %
100.0 %
305.5 %
NOTES: (1) Internet Usage and World Population Statistics are for June 30, 2008.
(2) Population numbers are based on data from the US Census Bureau .
(3) Internet usage information comes from data published by Nielsen//NetRatings,
by the International Telecommunications Union, by local NIC, and other reliable sources.
Source:

26. IPv6
การปรับปรุงที่ชัดเจนของ IPv6 คือความยาวของ IP address เปลี่ยนจาก 32 bits เป็น 128 bits การขยายดังกล่าวเพื่อรองรับการขยายของอินเตอร์เน็ต และเพื่อหลีกเลี่ยงการขาดแคลนของตำแหน่งเครือข่าย

27. Address space ส่วนแตกต่างที่เด่นที่สุดของ IPv6 ซึ่งพัฒนามาจาก IPv4 คือ
IPv4 ใช้ address ยาว 32-bit
(กว่า 4 พันล้าน addresses)
IPv6 ใช้ address ยาว 128-bit addresses
(กว่า 3.4×1038 addresses)

28. Figure IPv6 address

29. Figure 20.16 Abbreviated address

30. Figure 20.17 Abbreviated address with consecutive zeros

31. Figure CIDR address

32. Figure 20.19 Format of an IPv6 datagram

33. Figure 2 Format of an IPv6 datagram

34. Table 4 Comparison between IPv4 and IPv6 packet headers

35. Figure 20.20 Comparison of network layers in version 4 and version 6

37. Technology converging to 4G
คาดการณ์กันว่าทุกเทคโนโลยีจะต้องใช้ IP เป็นโปรโตคอลพื้นฐาน

38. Why so slow?
As of December 2005, IPv6 accounts for a tiny percentage of the live addresses in the publicly-accessible Internet, which is still dominated by IPv4.
Slow because of
classless addressing
network address translation (NAT),
When will we runout of IPv4 addresses?
APNIC (2003): the available space would last until 2023,
Cisco Systems (2005): available addresses would be exhausted in 4–5 years.

39. When is the change?
Although adoption of IPv6 has been slow, as of 2008, all United States government systems must support IPv6.
Meanwhile China is planning to get a head start implementing IPv6 with their 5 year plan for the China Next Generation Internet.
The country of Japan changed to IPv6.

40. Topics discussed in this section:
TRANSITION FROM IPv4 TO IPv6
Because of the huge number of systems on the Internet, the transition from IPv4 to IPv6 cannot happen suddenly. It takes a considerable amount of time before every system in the Internet can move from IPv4 to IPv6. The transition must be smooth to prevent any problems between IPv4 and IPv6 systems.
Topics discussed in this section:
Dual Stack Tunneling

41. Figure 20.21 Three transition strategies

42. Figure 20.22 Three transition strategies

43. Figure Tunneling

44. Figure 20.24 Header translation

45. ในส่วนของประเทศไทย
ในปัจจุบันได้มีการก่อตั้งคณะทำงานระดับประเทศขึ้นภายใต้ชื่อ Thailand IPv6 Forum
กิจกรรมในปัจจุบันของ Thailand IPv6 Forum ได้แก่ การเข้าร่วมเป็นสมาชิกของ Asia-Pacific IPv6 Task Force และการเชื่อมต่อแบบ Native IPv6

46. Summary Internet Protocol ARP RARP (obsolete) ICMP
Provides connectionless, best-effort delivery routing of datagrams, is not concerned with the content of the datagrams;
looks for a way to move the datagrams to their destination
ARP
Find MAC address of next-hop host
RARP (obsolete)
ICMP
Provides error control and messaging capabilities in unicasting