assigning ip addresses

Unicast

A type of network communication that sends data to only one specific host on the network.

Multicast

A type of network communication that sends data to all hosts in a defined multicast group.

Broadcast

A type of network communication that sends data to every host on the network.

IPv4 Broadcast Use

IPv4 uses broadcasts (like ARP) to locate other devices on the same network.

IPv6 Broadcast Use

IPv6 does not use broadcasting; it relies on multicasting instead.

Static IP Address

A manually configured IP address assigned to a device that does not change.

Dynamic IP Address

An IP address assigned automatically by a DHCP server each time a device connects to a network.

Example of Dynamic IPs

A home device might be 192.168.1.54, at school 10.0.1.37, and at Starbucks 192.168.0.11.

DHCP (Dynamic Host Configuration Protocol)

A protocol that automatically assigns IP addresses and network settings to devices without manual setup.

DHCP Advantage

Allows devices to easily move between LANs without reconfiguration.

DHCP Process Step 1 – Discover

The host broadcasts a DHCPDISCOVER message to find available DHCP servers.

DHCP Process Step 2 – Offer

A DHCP server responds with an available IP address, subnet mask, gateway, and lease details.

DHCP Process Step 3 – Request

The host sends a DHCPREQUEST message to accept the offered IP address.

DHCP Process Step 4 – Acknowledgement

The DHCP server confirms the assignment and leases the IP to the host for a set time.

DHCP Server Configuration – Scope

The range of IP addresses that can be distributed to clients.

DHCP Server Configuration – Subnet Mask

Defines the network segment to which the IP addresses belong.

DHCP Server Configuration – Default Gateway

The router’s address that devices use to reach other networks.

DHCP Server Configuration – Lease Time

The period an IP address is assigned before renewal or release, typically 3 days.

No DHCP Response

When a host receives no DHCP offers after sending a discover message.

APIPA (Automatic Private IP Addressing)

A fallback protocol allowing a device to self-assign an IP in the 169.254.0.0/16 range if no DHCP server responds.

APIPA Address Range

169.254.0.1 to 169.254.255.254.

APIPA Advantage

Enables local communication between devices even without a DHCP server (e.g., LAN gaming).

APIPA Limitation

Devices using APIPA cannot connect to routers, WANs, or the Internet.

IPv6 Address Assignment Methods

Static configuration, DHCPv6, or Stateless Address Autoconfiguration (SLAAC).

DHCPv6

A dynamic method that provides IPv6 addresses along with prefix length, lease time, and DNS info.

Router Advertisements (RAs)

IPv6 packets from routers that inform hosts how to reach networks beyond the LAN.

SLAAC (Stateless Address Autoconfiguration)

An IPv6 process where the host generates its own address using a router’s prefix and its MAC-based interface ID.