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Does subnet mask have to match?
Subnet masks always work from left to right. Devices are said to be within the same subnet if their IP Address starts with the same digits, but ends with a different set of digits. If the subnet mask is 255.255. 255.0, then the first three octets of all devices must be the same.
How do I find the default mask of an IP address?
These default masks are summarized in Table-5. Keep in mind that a subnet mask is not actually required to use one of these defaults because the IP address class can be determined by examining the first three bits of the IP address. If the first bit is 0, the address is Class A, and the subnet mask 255.0.
Can 2 subnets have the same subnet mask?
On a fundamental level, subnets are there to separate broadcast domains and improve efficiency. They’re not for sharing IP addresses. As an answer to your question above, the answer is: No you can’t… It is the address itself that must be unique.
How does a subnet mask work on an IP address?
This is done by borrowing bits from the host portion of the IP address, enabling more efficient use of the network address. A subnet mask defines which portion of the address is used to identify the network and which denotes the hosts.
What’s the default mask for a Class A network?
Each class has a different default subnet mask, and you identify the class by looking at the first octet of an IP address. However, there are also different types of IP addresses: static, dynamic, public, and private. Class A networks use a subnet mask of 255.0.0.0 and have 0-127 as their first octet.
How are the octets of an IP address represented?
Each of the octets can be represented in a decimal format, separated by decimal points. For more information on IP addressing, refer to IP Addressing and Subnetting for New Users. There are no specific requirements for this document. This document is not restricted to specific software and hardware versions.
How does CIDR address and subnet masking work?
Class A reserves the first octet for the network or subnet ID. Class B reserves the 2nd and 3rd, while Class C reserves the first three octets. This is rather inefficient because addresses will run out quickly. A scheme called CIDR (Classless Inter-Domain Routing) was developed to allow more networks and subnets to be created.