HP NetRider manual Setting an Internet Subnet Mask, Internet Address Class Default Subnet Mask

Configuring the Internet Address and Subnet Mask

Setting an Internet Subnet Mask

The Internet subnet mask is used to partition the host section of an Internet address into subnets. The default subnet mask depends on the class of the Internet address that you assigned.

The following table lists these defaults:

Internet Address Class	Default Subnet Mask
A	255.0.0.0
B	255.255.0.0
C	255.255.255.0

Do Not Define the Subnet Mask in the /etc/bootptab File

Although some BOOTP implementations allow you to define a subnet mask using the /etc/bootptab file, the network access server does not support this feature. For more information, refer to the network access server software installation documentation for your load host.

Changing the Subnet Mask

To change the subnet mask, use the CHANGE INTERNET SUBNET MASK command. The following example shows how to change the subnet mask to 255.255.255.0:

Local> CHANGE INTERNET SUBNET MASK 255.255.255.0

Changing the Subnet Mask to the Default Value

To return the subnet mask to its default value after changing it, do the following:

Step Action

1Enter the following command:

Local> DEFINE INTERNET SUBNET MASK NONE

2Reboot the access server.

Supernetted IP Addresses

The DNAS software supports the use of supernetted IP addresses. Supernetting allows you to configure the access server and its ports with a subnet mask shorter than the intrinsic subnet mask (for example, 255.255.255.0 for a Class C address). With

7-4 TCP/IP Network Characteristics