IP Addressing Terminology Page 82

Binary And Decimal Numbers Where do our numbers come from? Where do binary Numbers come from? Our numbers are Base ten-ten fingers and ten toes Binary originated with Leibniz (also calculus-developed for logic) Boole-but then found use in computers and electronics

Binary vs. Decimal Binary Number 1000 Decimal Number 1000 What is the difference? Write up numbers-1, 2, 4, 8 for Binary-1000 is eight! Switch to white board and do some examples! When Converting to Binary-Remember the 8 bit sequence 128 64 32 16 8 4 2 1

Convert Decimal to Binary 128 64 32 16 8 4 2 1 Convert 105 0 ? ? ? ? ? ? ? 0 1 ? ? ? ? ? ? 0 1 1 ? ? ? ? ? 0 1 1 0 ? ? ? ? 0 1 1 0 1 ? ? ? 0 1 1 0 1 0 0 1 = 105 Can I subtract 128? No Can I subtract 64? Yes- with 41 left Can I subtract 32? Yes-with 9 left Can I subtract 16? Can I subtract 8? Yes-1 left Can I subtract 4? 2? 1?

Convert Binary to Decimal 128 64 32 16 8 4 2 1 Convert 10110011 Add the decimal number when the bit is a 1 128 32 16 2 __1_ 179

IP addressing Scheme Dotted-decimal, as in 172.163.30.56 Binary, as in 10101100.00010000.00011110.00111000 Hexadecimal, as in AC.10.1E.38 (least likely)

IP Address Essential For each class you MUST know Address Class Range Reserved Addresses Default Subnet Mask Understand Network and Broadcast Address

Internet Address Classes Class A – Range 0.0.0.0 to 127.255.255.255 Class B – Range 128.0.0.0 to 191.255.255.255 Class C – Range 192.0.0.0 to 223.255.255.255 Class D – Range 224 to 239 (network address only) Class E – Range 240 to 247 (reserved for future use)

IP Addressing Rules Loopback address Broadcast address Network address Special-case source address Reserved IP addressing

Reserved Addresses

Class A Structure Range Default Subnet Mask Class A Addresses Network.node.node.node Range 0.0.0.0 through 126.255.255.255 Default Subnet Mask 255.0.0.0 Class A Addresses Valid hosts = 10.0.0.1 - 10.255.255.254 0’s & 255s are valid hosts but hosts bits cannot all be off or on at the same time! 224-2 = 22 Reserved Addresses: 10.0.0.0 through 10.255.255.255

Class B Structure Range Default Subnet Mask Class B Valid Host IDs Network.Network.node.node Range 128.0.0.0 through 191.255.255.255 Default Subnet Mask 255.255.0.0 Class B Valid Host IDs Valid hosts = 172.16.0.1 - 172.16.255.254 0’s & 255s are valid hosts but hosts bits cannot all be off or on at the same time! 216-2 = 214 Reserved Addresses: 172.16.0.0 through 172.31.255.255

Class C Structure Network.Network.Network.node Range 192.0.0.0 through 223.255.255.255 Default Subnet Mask 255.255.255.0 Class C Valid Host IDs Valid hosts = 192.168.100.1 - 192.168.100.254 28-2 = 26 Reserved Addresses: 192.168.0.0 through 192.168.255.255

IP Addressing Rules Loopback address Anything that starts with 127 127.0.0.1 Broadcast addresses Host portion is all 1 192.168.10.255 255.255.255.0 Network and special-case source addresses Host portion is all 0 192.168.10.0 Reserved IP addressing As seen on previous slides

Subnetworks Subnet masks ANDing Distinguish the network and host portions of an IP address Specify whether a destination address is local or remote ANDing

Key Subnetting Ideas If you know the subnet mask, figure out ranges Subtract Subnet mask from 256 Result is starting network address and block size Figure out network addresses Add block size to self up to subnet mask Figure out Broadcast addresses One less than next network address Figure out available addresses Between Network and Broadcast

Figuring Out subnets Figure out how many bits you have to play with You can steal from the host portion. How many subnets or hosts are needed? Use the 2n-2>= what you need formula Determine the subnet mask Make the bits you steal into 1’s and the rest into 0’s

Key Subnetting Ideas If you know the subnet mask, figure out ranges Subtract Subnet mask from 256 Result is starting network address and block size Figure out network addresses Add block size to self up to subnet mask Figure out Broadcast addresses One less than next network address Figure out available addresses Between Network and Broadcast

Basic Subnetting Example What is the network address for the following IP address, subnet mask combination: IP Address 210.32.100.70 Subnet Mask 255.255.255.240 210.32.100.0 210.32.100.32 210.32.100.64 210.32.100.79

Basic Subnetting Example IP Address 210.32.100.70 Subnet Mask 255.255.255.240 Step 1. 256-240=16 Step 2. 16, 32, 48, 64, 80, 96 (stop when you are past the number in question Step 3. 31, 47, 63, 79, 95, 111 Step 4. Answer-C

Basic Subnetting Example Which of the following are valid addresses for the following network (Choose 2) IP Address 180.64.96.0 Subnet Mask 255.255.224.0 180.64.1.1 180.64.110.240 180.64.35.10 180.64.120.255

Basic Subnetting Example IP Address 180.64.96.0 Subnet Mask 255.255.224.0 Step 1. 256-224=32 Step 2. 32, 64, 96, 128 (only need to go as far as question) Step 3. 63, 95, 127, 159 Step 4. Network 96 Range 180.64.96.1 through 180.64.127.254

CIDR Notation and subnet Masks / notation shows how many bits are 1 in subnet mask. For example: /8 = 11111111.00000000.00000000.00000000 =255.0.0.0 /12= 11111111.11110000.00000000.00000000 = 255.240.0.0 /16=11111111.11111111.00000000.00000000 =255.255.0.0

CIDR Notation and subnet Masks To figure subnet mask from / notation Step 1. Draw out bits, figure out how many bits are used in subnetted octet Step 2. For subnetted octect, write out 8 bit number with powers of 2 Step 3. Convert from Binary to Decimal Step 4. Write our subnet mask Step 5. Use number to figure Networks, Broadcasts and Ranges.

CIDR Example What is the subnet mask for the following address IP Address: 140.34.16.240 /20 255.255.0.0 255.255.248.0 255.240.0.0 255.255.240.0

CIDR Example IP Address: 140.34.16.240 /20 Step 1. 11111111.11111111.11110000.00000000 Step 2. 128 64 32 16 8 4 2 1 1 1 1 1 0 0 0 0 Step 3. 128+64+32+16=240 Step 4. 255.255.240.0 Step 5. Network-140.34.16.0 Broadcast-140.34.31.255 Range-140.34.16.1 through 140.34.31.254

Custom Subnet Masks Step 1: Determine the number of subnets needed Step 2: Determine the number of bits to borrow from the host portion Step 3: Determine the subnet mask Step 4: Determine the maximum number of hosts per subnetwork Step 5: Determine the subnetwork addresses for each subnet Step 6: Determine the address ranges for each subnetwork

Basic Subnetting Example What is the network address for the following IP address, subnet mask combination: IP Address 210.32.100.70 Subnet Mask 255.255.255.240 210.32.100.0 210.32.100.32 210.32.100.64 210.32.100.79

Basic Subnetting Example IP Address 210.32.100.70 Subnet Mask 255.255.255.240 Step 1. 256-240=16 Step 2. 16, 32, 48, 64, 80, 96 (stop when you are past the number in question Step 3. 31, 47, 63, 79, 95, 111 Step 4. Answer-C

Basic Subnetting Example What is the network address for the following IP address, subnet mask combination: IP Address 210.32.100.70 Subnet Mask 255.255.255.240 210.32.100.0 210.32.100.32 210.32.100.64 210.32.100.79

Basic Subnetting Example Which of the following are valid addresses for the following network (Choose 2) IP Address 180.64.96.0 Subnet Mask 255.255.224.0 180.64.1.1 180.64.110.240 180.64.35.10 180.64.120.255

Basic Subnetting Example IP Address 180.64.96.0 Subnet Mask 255.255.224.0 Step 1. 256-224=32 Step 2. 32, 64, 96, 128 (only need to go as far as question) Step 3. 63, 95, 127, 159 Step 4. Network 96 Range 180.64.96.1 through 180.64.127.254

Basic Subnetting Example Which of the following are valid addresses for the following network (Choose 2) IP Address 180.64.96.0 Subnet Mask 255.255.224.0 180.64.1.1 180.64.110.240 180.64.35.10 180.64.120.255

CIDR Notation and subnet Masks / notation shows how many bits are 1 in subnet mask. For example: /8 = 11111111.00000000.00000000.00000000 =255.0.0.0 /12= 11111111.11110000.00000000.00000000 = 255.240.0.0 /16=11111111.11111111.00000000.00000000 =255.255.0.0

CIDR Notation and subnet Masks To figure subnet mask from / notation Step 1. Draw out bits, figure out how many bits are used in subnetted octet Step 2. For subnetted octect, write out 8 bit number with powers of 2 Step 3. Convert from Binary to Decimal Step 4. Write our subnet mask Step 5. Use number to figure Networks, Broadcasts and Ranges.

CIDR Example What is the subnet mask for the following address IP Address: 140.34.16.240 /20 255.255.0.0 255.255.248.0 255.240.0.0 255.255.240.0

CIDR Example IP Address: 140.34.16.240 /20 Step 1. 11111111.11111111.11110000.00000000 Step 2. 128 64 32 16 8 4 2 1 1 1 1 1 0 0 0 0 Step 3. 128+64+32+16=240 Step 4. 255.255.240.0 Step 5. Network-140.34.16.0 Broadcast-140.34.31.255 Range-140.34.16.1 through 140.34.31.254

CIDR Example What is the subnet mask for the following address IP Address: 140.34.16.240 /20 255.255.0.0 255.255.248.0 255.240.0.0 255.255.240.0

Custom Subnet Masks Step 1: Determine the number of subnets needed Step 2: Determine the number of bits to borrow from the host portion Step 3: Determine the subnet mask Step 4: Determine the maximum number of hosts per subnetwork Step 5: Determine the subnetwork addresses for each subnet Step 6: Determine the address ranges for each subnetwork