Network Basic v0.1. Network Basic v0.1. Chapter 3 Internet Protocol. Chapter 3. Internet Protocol

Transcription

1 Network Basic v0.1 Chapter 3. Internet Protocol 1 Network Basic v0.1 Chapter 3 Internet Protocol 1. The Role of Network Layer 2. IP Protocol Feature 3. IP Packet Routing 5. DHCP 6. NAT 2 1

2 네트워크 ICONs 3 Chapter 3 IP, TCP, UDP 1. The Role of Network Layer 2. IP Protocol Feature 3. IP Packet Routing 5. DHCP 6. NAT 7. Network Layer Troubleshooting 8. Quiz 4 2

3 1. The Role of Network Layer The Goal of Network Layer Protocol Provides transparent Packet Delivery 5 1. The Role of Network Layer The Goal of Network Layer Protocol Network Layer Protocols forward encapsulated Transport Layer PDUs between hosts 6 3

4 1. The Role of Network Layer Various Network Layer Protocols To be only IP protocol for Network Layer? 7 2. IP Protocol Feature The Characteristics of IP Connectionless, Best Effort, Media Independent Like as a Mail Man 8 4

5 2. IP Protocol Feature The Characteristics of IP The transport Layer segments are encapsulated as packets 9 2. IP Protocol Feature IPv4 Header Identify the major header fields in the IPv4 protocol and describe each field's role in transporting packets 10 5

6 2. IP Protocol Feature IPv4 Header Version - Version number (4 bits) Header Length - Header length in 32-bit words (4 bits) Priority and Type of Service - How the datagram should be handled. The first 3 bits are priority bits (8 bits). Total Length - Total length (header + data) (16 bits) Identification - Unique IP datagram value (16 bits) Flags - Specifies if fragmenting should occur (3 bits) [0,MF,DF] Fragment Offset - Provide fragmentation of datagram to allow differing MTUs in network (13 bits) TTL - Time-To-Live (8 bits) Protocol - Upper-layer (Layer 4) protocol sending the datagram (8 bits) Header Checksum - Integrity check on the header (16 bits) Source IP Address - 32-bit source IP addresses (32 bits) Destination IP Addresses - 32-bit destination IP addresses (32 bits) IP Options - Network testing, debugging, security, and others (0 or 32 bits if any) Data - Upper-layer protocol data (varies) IP Protocol Feature IPv6 Header IPv6 has simple Header and large IP address fields (128 bit) 12 6

7 3. IP Packet Routing Routing Feature Gateways enable communications between Networks IP Packet Routing Routing Feature Router uses Routing Table to route packets 14 7

8 3. IP Packet Routing Routing Feature IP Packet Routing Routing Feature Trace the steps of several IP packets as they are routed through several gateways from devices on one sub network to devices on other sub networks 16 8

9 3. IP Packet Routing Routing Feature IP Packet Routing Routing Feature 18 9

10 3. IP Packet Routing Manipulate Routing Table Static routing vs Dynamic routing -. Static Routing is directly configured in Router by administrator IP Packet Routing Manipulate Routing Table Static routing vs Dynamic routing -. Dynamic Routing : Routers learn Routing entries from each other 20 10

11 IP Address Describe the general role of 8-bit binary in network addressing and convert 8-bit binary to decimal 21 IP Address Practice converting 8-bit binary to decimal 22 11

12 Classify and Define IPv4 Addresses Three types of addresses in the network 23 Classify and Define IPv4 Addresses 24 12

13 Classify and Define IPv4 Addresses 25 Classify and Define IPv4 Addresses 26 13

14 Classify and Define IPv4 Addresses Identify the historic method for assigning addresses and the issues associated with the method 27 Private and Reserved IP Address Private Address [RFC 1918] /8 ( ~ ) /12 ( ~ ) /16 ( ~ ) Host Loopback IP address /8 ( ~ ) DHCP Fault IP address /16 ( ~ ) TEST-NET IP address /24 ( ~ ) Default / Broadcast & Other unique IP /

15 Subnet Mask Subnet Mask 자신이속한네트워크주소를표시하기위해사용 Subnet Mask 와 IP Address 의 AND 연산을통해 Local 또는 Remote Network 을판단 Local 이면 ARP를통한 Broadcast 통신이 개시되며 , Remote 이면라우팅테이블참조 AND Source IP Address AND Destination IP Address Assigning IP Address Describe the process for requesting IPv4 public addresses, the role ISPs play in the process, and the role of the regional agencies that manage IP address registries 30 15

16 Calculating IP Address 31 Calculating IP Address 32 16

17 5. DHCP (Dynamic Host Configuration Protocol) DHCP Layer 2 Loop incurs MAC Table instability of Switches DHCP (Dynamic Host Configuration Protocol) DHCP Operation How DHCP dynamically assigns an IP address to a client 34 17

18 5. DHCP (Dynamic Host Configuration Protocol) DHCP Operation How DHCP dynamically assigns an IP address to a client DHCP (Dynamic Host Configuration Protocol) DHCP Operation 36 18

19 5. DHCP (Dynamic Host Configuration Protocol) DHCP Operation NAT (Network Address Translation) NAT Public and Private Internet Addresses 38 19

20 6. NAT (Network Address Translation) NAT An IP address is either local or global. Local IP addresses are seen in the inside network. Global IP addresses are seen in the outside network NAT (Network Address Translation) PAT (Port Address Translation) IP Masquerading 내부의 Local IP address 가전역 IP address 의 Port 번호에매칭되는구조. NAT Table 은이를 Translation 하기위해관리됨

21 6. NAT (Network Address Translation) PAT (Port Address Translation) IP Masquerading PAT NAT Table Pro Inside Global Inside Local Outside Local Outside Global tcp : : : :80 tcp : : : :