I took three basic TCP/IP classes and still did not quite understand subnet masking. Then I took my first Cisco basic class and the instructor handed out a cheat sheet of binary patterns. All a subnet mask is is a binary bit pattern of all 1's up to a certain point, and anything after the 1's is host address. Example: subnet mask 255.255.0.0
A subnet mask works like a filter with the mask identifying the IP address bits that represent the network ID with a 1, and the bits that represent the host ID with a 0. The more host bits you have, the more devices that can connect to your subnet at the expense of the total number of sub networks you can set up, and visa-versa. The subnet mask is always a string of ones on the left followed by a string of zeroes on the right. Dec 19, 2019 · A subnet mask is used to divide an IP address into two parts. One part identifies the host (computer), the other part identifies the network to which it belongs. To better understand how IP addresses and subnet masks work, look at an IP (Internet Protocol) address and see how it is organized. The IP subnet mask is a key component to determine the length of a subnet. The subnet mask is basically a mask of continguos bits all set to ‘1’ starting from the left side. All other bits are set to ‘0’. The next table illustrates all the valid subnet masks: With Subnet Masks Introduction, another concept was introduced to help representing Subnet masks or the Network Portion. Classless Internet Domain Routing (CIDR) made it simpler to write down the subnet mask in a short way as prefix. 255.0.0.0 is equal to prefix /8. Jun 10, 2020 · A2- Yes you only need 8 bits for 100 hosts and both subnet masks would give you that. A subnet mask of 255.255.255.0 would give you lots of networks (2 16) and 254 hosts. A subnet of 255.255.0.0 would give you lots of hosts (approx 2 16) and 256 networks. A3 – the network has 8 bits and so does the node component.
The key to understanding this is that your host looks,at the subnet mask and the address it's trying to reach. If the address is local (matches the subnet mask) it is broadcast out the local net. If it doesn't match it is sent to the default gateway for routing.
May 13, 2020 · Add the IP address and subnet mask and click "Add"; For this example, the laptop/computer IP address is 192.168.2.160 and the subnet mask is 255.255.255.0 . See below the sequence of pictures that illustrate this process
A Subnet mask can be written in two ways; in full form and in abbreviated form. In full form a decimal value of each octet is written along with IP address. In abbreviated form only the number of network bits are written along with IP address. Following table lists some examples of both types.
Working with Subnets and Subnet Masks 74. Defining subnet masks 76. Why a network has a mask when it has no subnets 76. Subnetting 101 77. Letting the DHCP Protocol Do the Work for You 79. One administrator’s nightmare is another’s fantasy 80. Understanding how the DHCP protocol works —it’s client/server again 81 Dec 20, 2014 · For example, a subnet mask of 255.255.255.0 (binary equivalent = 11111111.11111111.11111111.00000000) inverts to a wildcard mask of 0.0.0.255. A wild card mask defines matching rule like a 0 in a bit position means that the corresponding bit position in the address of the Access Control Lists (ACL) statement must match the bit position in the