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CN2668 Routers and Switches. Kemtis Kunanuraksapong MSIS with Distinction MCTS, MCDST, MCP, A+. Agenda. Chapter 4: IP Addressing Exercise Quiz. Addressing on a Network. Four methods are used to identify devices and programs MAC Address Using an IP address Using character-based names
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CN2668Routers and Switches Kemtis Kunanuraksapong MSIS with Distinction MCTS, MCDST, MCP, A+
Agenda • Chapter 4: IP Addressing • Exercise • Quiz
Addressing on a Network • Four methods are used to identify devices and programs • MAC Address • Using an IP address • Using character-based names • Such as domain names, host names, and NetBIOS names • Host names and NetBIOS names are often just called computer names • Using a port address
IP Address (IPv4) • A number that uniquely identifies a device • Network ID – for the network segment to identifies the host network • Host ID – identifies the host within the network • Consist of a 32-bit binary number • Octet • Divided into four groupings of eight bits each • 192.168.0.1 = 11000000.10101000.00000000.00000001
IP Address Classes • Class A – 0.0.0.0 to 126.255.255.255 • Class B - 128.0.0.0 to 191.255.255.255 • Class C - 192.0.0.0 to 223.255.254.255 • Class D - 224.0.0.0 to 239.255.255.255 • Are used for multicasting to a group • Class E - 240.0.0.0 to 255.255.255.255 • Are reserved for experimental and future use • Class D and E Are not assigned to individual devices • The first and last of addresses of each class are reserved
IP Address Validity • The first byte of the IP address must fall within the following ranges • 1 through 126 • 128 through 191 • 192 through 223 • IP addresses that begin with 0, 127, or 224 through 225 are invalid • The host ID cannot be all binary 0s or 1s (all 0s or all 255s) • No number in an IP address can be greater than 255
Private IP Ranges • In your own network • 10.0.0.0 through 10.255.255.255 • 172.16.0.0 through 172.31.255.255 • 192.168.0.0 through 192.168.255.255 • They will not be routable on the Internet • They use gateway to get out to Internet
Network Addressing (Subnet Mask) • Tells a TCP/IP host how to interpret IP address by defining what portion of the IP address is the network ID and host ID • The default subnet masks • Class A: 255.0.0.0 • Class B: 255.255.0.0 • Class C: 255.255.255.0 • Classless interdomain routing (CIDR) notation • 192.168.0.0/24
Subnet Masks • To determine whether a destination host is on the same or a different network • If on the remote network, it will use default gateway to communicate • AND operation to determine network and host • Classfulsubnet mask • Subnet masks that use either all ones or zeroes in an octet
Broadcast Address • If all the binary digits in the host identifier are ones • 199.192.165.0/24 has 199.192.165.255 as broadcast address • 199.192.65.32/27 has 199.192.65.63 as broadcast address • Flooded broadcasts (255.255.255.255) • Broadcasts for any subnet • Directed broadcasts • Broadcasts for specific subnet
Subnet Masking • To match the physical layout of the organization • To match the administrative structure • To plan for future growth • To reduce network traffic • See Table 4-3 on Page 96
Subnetting Formulas • 2y = # of usable subnets • Y is the number of bits borrowed • 2x-2 = # of usable hosts per subnet • X is the number of bits remaining in the host field after borrowing • 199.4.10.0/28 (See Figure 4-13 on Page 100) • 4 bits borrowed for the mask • 16 usable subnets • 4 bits left for host • 14 usable hosts per subnet
Summarization (supernetting) • To allow many IP subnets to be advertised as one. • See Table 4-6 on Page 102 • All 4 subnets share the same left 22 bits • Routing table can aggregate it into 213.64.132.0/22 rather than 4 subnets
VLSM • Variable Length Subnet Masking • a technique that allows network administrators to divide an IP address space to subnets of different sizes. • Commonly done with Class C address • RIP Version 1 and IGRP do not support • They do not carry subnet mask information in their routing table updates • With main IP address, you should start with the highest host required • See http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800a67f5.shtml#vlsmexample
VLSM (2) • 204.17.5.0 • netA: must support 14 hosts • netB: must support 28 hosts • netC: must support 2 hosts • netD: must support 7 hosts • netE: must support 28 host • Calculate the subnet mask • netB: 204.15.5.0/27 host address range 1 to 30 • netE: 204.15.5.32/27 host address range 33 to 62 • netA: 204.15.5.64/28 host address range 65 to 78 • netD: 204.15.5.80/28 host address range 81 to 94 • netC: 204.15.5.96/30 host address range 97 to 98
Hexadecimal Numbers • Base 16 (0 – F) • Easiest way to convert any base number is • From X Base -> Binary -> X Base
IPv4 versus IPv6 • 128 bits and expressed as hexadecimal numbers • 32 numbers divide into 8 groups of 4 numbers each • 2001:702:21::/48 • The first 48 bits identify the network • :: means the rest are zeroes
IPv6 Transition • Dual Stack • Enabling IPv6 on all routers, switches, and end nodes. • IPv4 is still enable • Tunneling • Encapsulates IPv6 traffic inside IPv4 packets • To send IPv6 packets through the network that does not support IPv6 (v6 -> v4 -> v6)
Assignment • Review Questions • 1 – 24 • Case Projects • 2