Transmission Control Protocol/Internet Protocol - Laboration [Mina svar på frågorna är markerade med fet stil.] Summary Class Start Finish Networks Hosts A 1 126 126 16,777,214 B 128 191 16,384 65,534 C 192 223 2,097,152 254 The subnet mask is used to extract the network ID. Subnetting is the process of turning more bits on (to 1) in the subnet mask. The numbers that can appear in an own subnet mask are 0, 192, 224, 240, 248, 252, 254, 255 and 128. The number 128 is used only when subnetting with more than one octet. You should have a single subnet mask for your entire organization. You vill lose addresses when you need to subnet. When you subnet, you vill have 2^(number of subnet bits) - 2 networks and 2^(number of remaining bits) - 2 hosts per subnet. Custom (own) subnet masks are allways appended to the normal (default) subnet mask. Supernetting joins groups addresses; you will allways join 2^x networks together. Supernetting is performed to give you a single address on the Internet and normally happens at your Internet Service Provider. Determining bits Used. Determine the number of bits needed to accommodate the number of networks given: 84 networks needed 7 bits. 145 networks needed 8 bits. 7 networks needed 3 bits. 1 network needed 2 bits. 15 networks needed 5 bits. 222 networks needed 8 bits. 92 networks needed 7 bits. 129 networks needed 8 bits. 384 networks needed 9 bits. 9 networks needed 4 bits. Calculating the Subnet Mask by Number of Subnets. Given a network ID and the required number of subnets, determine the subnet mask and the number of hosts per subnet: Network ID 148.25.0.0 with 37 subnets. Subnet mask is 255.255.252.0 with 1 022 hosts per subnet. Network ID 198.63.24.0 with 2 subnets. Subnet mask is 255.255.255.192 with 62 hosts per subnet. Network ID 110.0.0.0 with 1000 subnets. Subnet mask is 255.255.192.0 with 16 382 hosts per subnet. Network ID 175.23.0.0 with 550 subnets. Subnet mask is 255.255.255.192 with 62 hosts per subnet. Network ID 209.206.202.0 with 60 subnets. Subnet mask is 255.255.255.252 with 2 hosts per subnet. Network ID 98.25.0.0 with 737 subnets. Subnet mask is 255.255.192.0 with 16 382 hosts per subnet. Network ID 222.125.60.0 with 38 subnets. Subnet mask is 255.255.255.252 with 2 hosts per subnet. Network ID 223.21.25.0 with 14 subnets. Subnet mask is 255.255.255.240 with 14 hosts per subnet. Network ID 154.25.0.0 with 30 subnets. Subnet mask is 255.255.248.0 with 2 046 hosts per subnet. Network ID 63.0.0.0 with 131000 subnets. Subnet mask is 255.255.255.128 with 126 hosts per subnet. Calculating the Subnet Mask by Number of Hosts. Determine the number of subnets that vill be available: Network 63.0.0.0 with a maximum of 100 host per subnet. Subnet mask 255.255.255.128 with 131 072 subnet available. Network 198.53.25.0 with a maximum of 100 host per subnet. Subnet mask 255.255.255.198 with 2 subnet available. Network 154.25.0.0 with a maximum of 1500 host per subnet. Subnet mask 255.255.248.0 with 32 subnet available. Network 121.0.0.0 with a maximum of 2000 host per subnet. Subnet mask 255.255.248.0 with 8192 subnet available. Network 210.58.110.0 with a maximum of 2 host per subnet. Subnet mask 255.255.255.252 with 64 subnet available. Network 164.220.0.0 with a maximum of 1005 host per subnet. Subnet mask 255.255.252.0 with 64 subnet available. Network 103.0.0.0 with a maximum of 12000 host per subnet. Subnet mask 255.255.192.0 with 1 024 subnet available. Network 209.50.50.0 with a maximum of 10 host per subnet. Subnet mask 255.255.255.240 with 16 subnet available. Network 209.50.50.0 with a maximum of 2 host per subnet. Subnet mask 255.255.255.252 with 64 subnet available. Network 209.50.50.0 with a maximum of 16 host per subnet. Subnet mask 255.255.255.224 with 8 subnet available. Determining Host IDs. For each of the following subnet IDs and subnets masks, determine the valid host IDs: Subnet ID 148.56.64.0 with the subnet mask 255.255.252.0. Valid host ID from 148.56.64.1 to 148.56.67.254. Subnet ID 52.36.0.0 with the subnet mask 255.255.0.0. Valid host ID from 52.36.0.1 to 52.36.255.254. Subnet ID 198.53.24.64 with the subnet mask 255.255.255.192. Valid host ID from 198.53.24.65 to 198.53.24.126. Subnet ID 132.56.16.0 with the subnet mask 255.255.248.0. Valid host ID from 132.56.16.1 to 132.56.23.254. Subnet ID 152.56.144.0 with the subnet mask 255.255.254.0. Valid host ID from 152.56.144.1 to 152.56.145.254. You have an assigned IP adress of 100.0.0.0. Maximize the number of available hosts per subnet Subnet mask 255.192.0.0. 2 subnets available with 4 194 302 hosts each. Subnet mask 255.224.0.0. 6 subnets available with 2 097 150 hosts each. Subnet mask 255.240.0.0. 14 subnets available with 1 048 574 hosts each. Subnet mask 255.248.0.0. 30 subnets available with 524 286 hosts each. Subnet mask 255.252.0.0. 62 subnets available with 262 142 hosts each. Determining a range of Hosts IDs from a Host ID. Determine the range of hosts IDs into which it falls: IP address of 23.25.68.2 with subnet mask 255.255.224.0. Range from 23.25.64.1 to 23.25.95.254. IP address of 198.53.64.7 with subnet mask 255.255.255.0. Range from 198.53.64.1 to 198.53.64.254. IP address of 131.107.56.25 with subnet mask 255.255.248.0. Range from 131.107.56.1 to 131.107.63.254. IP address of 148.53.66.7 with subnet mask 255.255.240.0. Range from 148.53.64.1 to 148.53.79.254. IP address of 1.1.0.1 with subnet mask 255.255.0.0. Range from 1.1.0.1 to 1.1.255.254. Other questions: Why is subnetting required? Det finns i nuläget inte tillräckligt många IP-adresser så de räcker till alla. What does subnetting do from a binary perspective? Blockerar nät-id-delens bitar. How many different subnet masks are required for an organization with 17938 hosts? 7 stycken. What is the function of a subnet mask? Specificerar vilket nät en viss IP-adress befinner sig på. What is the least number of bits that you can subnet on? 9 stycken. What is the first function that IP must perform? How does it do it? IP jämför mottagarens IP-adress med subnätmasken för att avgöra om mottagaren sitter på samma subnät som avsändaren eller inte. What are the two parts of the TCP/IP adress? Net-ID och Host-ID. How does the computer see a TCP/IP address? Som ettor och nollor - binär form. You have an assigned IP address of 100.0.0.0 and only eight subnets, buy you anticipate adding two more subnets next year. You want to maximize the number of available hosts you can have on each subnet.What subnet mask should you use? 255.240.0.0 (med 1 048 574 Hosts/Subnet). © 1999-2001 Roger Strömbäck