Fundamental IPV4

• Subnetting is the process of splitting up a network address into smaller networks. /etc/inet/ netmasks contains the masks to identify the network portion of an IP address.

• VLSM allows subnetting with each subnetwork being able to be a different size, each with its own network mask.

The files used to configure a network interface are

• /etc/hostname.< interface > ” Contains the hostname or IP address that is associated with the interface.

• /etc/inet/ hosts ” Provides IPv4 address “to “hostname mapping.

• /etc/nodename ” Contains a single entry, the authoritative hostname of the system.

To change the hostname, either run sys-unconfig and re-enter the system identification information when the system reboots or edit the following files:

• /etc/inet/hosts

• /etc/nodename

• /etc/hostname.< interface > , such as /etc/hostname.hme0

• /etc/net/ticlts/hosts

• /etc/net/ticots/hosts

• /etc/net/ticotsord/hosts

Logical interfaces allow the assignment of more than one IP address to a physical interface. To configure a logical interface for an hme0 interface with an IP address of 192.168.28.122 :

 ultra10# ifconfig hme0:1 plumb 192.168.28.122 up 

To use the next available logical interface number:

 ultra10# ifconfig hme0 addif 192.168.28.122 up 

Both of the previous commands configure and enable the logical interface.

To unconfigure a logical interface, hme0:2 :

 ultra10# ifconfig hme0:2 down unplumb 

The down option should come before the unplumb option to remove the logical interface cleanly and not risk any data loss.