2 IP Addressing Introduction IPv4 addresses are 32 bits in length.IPv4 broken into four bytes (called octets), with a dot between each byte.Classes of AddressesUsed for networkClass AClass BClass CMulticastClass DFutureClass E
4 IP Address ComponentsIP address has two part, the first part is the network which identifies the network where the system is connected, and a second part is the Host which identifies that particular system on the network.
6 Guidelines for IP Addressing You must not use 127 for the first octet of the network ID. This value is reserved for diagnostic purposes.You must not use all 1s (binary) for the host ID. If all bits are set to 1, the address is interpreted as a broadcast address.You must not use all 0s for the host ID. If host bits are set to 0, some TCP/IP implementations interpret this as a subnetwork address.You must not duplicate host IDs within a network segment.
7 Identifying IP Addresses Determine which of the following IP addresses is valid or invalidInvalid (256)ValidInvalid (127)Invalid (Broadcast)
8 What Is a Subnet?A subnet is a physical segment of a network that is separated from the rest of the network by a router or routers.A network of multiple subnets connected by routers is often referred to as an internetwork.
9 Creating a Subnet How many subnets? How many hosts per subnet? 2X = number of subnets you need (X represents subnet bits)How many hosts per subnet?2Y - 2 = number of hosts (Y represents host bits)What are the valid subnets?256 – subnet maskWhat’s the broadcast address for each subnet?What are the valid hosts? Valid hosts are the numbers between the subnets, omitting all the 0s and all 1s.
10 Example 1 192.168.10.0 = Network address 255.255.255.192 = Subnet mask How many subnets? Since 192 is 2 bits on ( ), the answer would be 22.How many hosts per subnet? We have 6 host bits off ( ), so the equation would be 26 – 2 = 62 hosts.What are the valid subnets? 256 – 192 = 64. Remember, we start at zero and count in our block size, so our subnets are 0, 64, 128, and 192.What’s the broadcast address for each subnet? The number right before the value of the next subnet is all host bits turned on and equals the broadcast address.
11 Example 1 192 128 64 The subnets 193 129 65 1 The first host 254 190 What are the valid hosts?19212864The subnets193129651The first host25419012662The last host25519112763The broadcast address
12 Example 2 192.168.10.0 = Network address 255.255.255.224 = Subnet mask How many subnets? 224 is , so our equation would be 23 = 8.How many hosts? 25 – 2 = 30.What are the valid subnets? 256 – 224 = 32. We just start at zero and count to the subnetmask value in blocks (increments) of 32: 0, 32, 64, 96, 128, 160, 192, 224.What’s the broadcast address for each subnet (always the number right before the next subnet)?What are the valid hosts (the numbers between the subnet number and the broadcast address)?
13 Example 2 The subnets The first host The last host The broadcast What are the valid hosts?224192160128966432The subnets2251931611299765331The first host254222190158126946230The last host255223191159127956331The broadcastaddress
14 Exercise 1You are given a Class C network ( ) and you have 4 segments in your network, where the largest segment has 50 hosts. What subnet mask should you use and what is the layout of your addresses?
15 Answer 1 Subnet Mask = 255.255.255.192 192 128 64 The subnets 193 129 The subnets193129651The first host25419012662The last host25519112763The broadcast address
16 Exercise 2You are given the following address: /29. What type of address is this network, broadcast, or host?Answer: -This is a broadcast address.
17 Exercise 3You are given the following address: /22. What type of address is this network, broadcast, or host?Answer: -This is a host address.