What is the default subnet of Class A?
Andrew Henderson
Updated on March 16, 2026
What is the default subnet of Class A?
255.0.0.0
Class A networks use a default subnet mask of 255.0. 0.0 and have 0-127 as their first octet.
How do you find the subnet mask of a Class A?
Valid subnet address: To figure out the valid subnet address, simply subtract the subnet mask from 256. For example, if you had a Class A mask of 255.240. 0.0, the equation would be 256-240=16….128.0 subnet:
- Subnet: 10.0. 128.0.
- Broadcast: 10.0. 255.255.
- Valid host range: 10.0. 128.1 through 10.0. 255.254.
What is the default subnet mask of a Class A ipv4 address?
The three default subnet masks are 255.0. 0.0 for Class A, 255.255. 0.0 for class B, and 255.255. 255.0 for Class C.
What is the default subnet mask for a Class A network Mcq?
Explanation: The mask 255.255. 254.0 (/23) used with a Class A address means that there are 15 subnet bits and 9 host bits. The block size in the third octet is 2 (256 – 254). So this makes the subnets in the interesting octet 0, 2, 4, 6, etc., all the way to 254.
Is 255.255 255.255 IP address valid?
No, it is not possible to have any source 255.255. 255.255 as IP Address because this IP Address is already reserved for the broadcast address.
What is a 255.255 255.0 subnet?
A subnet mask of 255.255. 255.0 allows for close to 256 unique hosts within the network (since not all 256 IP addresses can be used). This is the default subnet mask used by Class B networks and provides up to 65,536 IP addresses (256 x 256). The largest Class A networks use a subnet mask of 255.0.
What is a Class A subnet?
A Class A IP address reserves 8 bits for a network with 24 bits dedicated to hosts. Its IP address spans from 0 to 126. The Class A subnet mask is 255.0. 0.0. Network addresses for these range from 128 to 191.
What are the 3 classes of subnet mask?
Class A, B, and C networks have natural masks, or default subnet masks:
- Class A: 255.0. 0.0.
- Class B: 255.255. 0.0.
- Class C: 255.255. 255.0.
What is a Class B IP address?
Class B IP addresses are used for medium and large-sized networks in enterprises and organizations. They support up to 65,000 hosts on 16,000 individual networks. Class C addresses are most common and used in small business and home networks. These support up to 256 hosts on each of 2 million networks.
What are default subnet mask for each classes?
Default Subnet Mask
| IP Address Class | Default Subnet Mask |
|---|---|
| Class A | 255.0.0.0 |
| Class B | 255.255.0.0 |
| Class C | 255.255.255.0 |
Which of the following is default mask of Class A?
Default Subnet Mask
| IP Address Class | Default Subnet Mask |
|---|---|
| Class A | 255.0.0.0 |
| Class B | 255.255.0.0 |
| Class C | 255.255.255.0 |
What does a subnet mask of 255.255 255.0 mean?
A class C network would have a subnet mask of 255.255. 255.0 which means that 24 bits are used for the network. In CIDR notation this is designated by a /24 following the IP address.
What is the default subnet mask for Class A subnet?
The mask. Class A subnet masks must start with 255.0.0.0 at a minimum, because the whole first octet of an IP address (the IP address describes the specific location on the network) is used to define the network portion (the network portion describes the “street” that IP addresses are located on).
What is a Class A subnet in IPv4?
IPv4 Class A Subnets In Class A, solely the first octet is used as Network symbol and remainder of 3 octets are used to be assigned to Hosts (i.e. 16777214 Hosts per Network). to create a lot of subnet in class A, bits from Host part are borrowed and therefore the subnet mask is modified consequently.
What is a non-subnetted Class A network?
In essence, a non-subnetted class A, B or C network can be considered the “default case” of the more general, custom-subnetted network. Specifically, it is the case where we choose to divide the host ID so that zero bits are used for the subnet ID and all the bits are used for the host ID. I realize that this seems like a bit of a semantic game.
What are the default subnets that divide on octet boundaries?
There are a small number of custom subnets that divide on octet boundaries as well. These are: 255.255.0.0:,This is the default mask for Class B, but can also be the custom subnet mask for dividing a Class A network using 8 bits for the subnet ID (leaving 16 bits for the host ID).
