Chapter 6-Addressing the Network: IPv4

TEST-NET Addresses

-: The address block 192.0.2.0 to 192.0.2.255 (192.0.2.0 /24) is set aside for teaching and learning purposes

IP Address Classes - ADD

-Class A- 128 1-126 255.0.0.0. Class B- 128-191 255.255.0.0 Class C 192-223 255.255.255.0 Class D 224-239 N/A-Multicast Class E 240-255 N/A-Experimental

Directed Broadcast

A directed broadcast is sent to all hosts on a specific network.

Broadcast address

A special address used to send data to all hosts in the network. To send data to all hosts in a network, a host can send a single packet that is addressed to the broadcast address of the network. -The broadcast address uses the highest address in the network range.

The IPv4 address range

From 0.0.0.0 To 255.255.255.255.

PRIVATE ADDRESSES

From 10.0.0.010 To 255.255.255 (10.0.0.0 /8) From 172.16.0.0 To 172.31.255.255 (172.16.0.0 /12) From 192.168.0.0 To 192.168.255.255 (192.168.0.0 /16)

Reserved Link Local

From 224.0.0.0 To 224.0.0.255. (part of multicast)

Multicast Addresses

From 224.0.0.0 To 239.255.255.255.

Globally scoped addresses

From 224.0.1.0 To 238.255.255.255. (part of multicast)

Experimental Addresses

From 240.0.0.0 To 255.255.255.254

Multicast Clients

Hosts that wish to receive particular multicast data are called multicast clients. The multicast clients use services initiated by a client program to subscribe to the multicast group.

Link-Local Addresses

IPv4 addresses in the address block 169.254.0.0 to 169.254.255.255 (169.254.0.0 /16) are designated as link-local addresses. -These addresses can be automatically assigned to the local host by the operating system in environments where no IP configuration is available

Ping

Is a utility for testing IP connectivity between hosts. Ping sends out requests for responses from a specified host address.

Digital logic

Is applied for their interpretation by the computer. We use the dotted decimal

The prefix length

Is the number of bits in the address that gives us the network portion. -For example, in 172.16.4.0 /24, the /24 is the prefix length - it tells us that the first 24 bits are the network address.

Loopback

One such reserved address is the IPv4 loopback address 127.0.0.1. -The loopback is a special address that hosts use to direct traffic to themselves.

Network address

The address by which we refer to the network. Within the IPv4 address range of a network, the lowest address is reserved for the network address.

Host addresses

The addresses assigned to the end devices in the network

Limited Broadcast

The limited broadcast is used for communication that is limited to the hosts on the local network. Routers do not forward this broadcast. -Packets addressed to the limited broadcast address will only appear on the local network. For this reason, an IPv4 network is also referred to as a broadcast domain.

Multicast

The process of sending a packet from one host to a selected group of hosts. It reduces traffic by allowing a host to send a single packet to a selected set of hosts.

ISP Services:

To get access to the services of the Internet, we have to connect our data network to the Internet using an Internet Service Provider (ISP).

Pinging the Local Loopback

To perform this test, we ping the special reserve address of local loopback (127.0.0.1). -A response from 127.0.0.1 indicates that IP is properly installed on the host.

Time to Live (TTL)

Traceroute makes use of a function of the Time to Live (TTL) field in the Layer 3 header and ICMP Time Exceeded Message

Round Trip Time (RTT)

Using traceroute provides round trip time (RTT) for each hop along the path and indicates if a hop fails to respond.

Pinging the Gateway Address

You can also use ping to test the host ability to communicate on the local network. -This is generally done by pinging the IP address of the gateway of the host

Traceroute (tracert)

is a utility that allows us to observe the path between these hosts. -The trace generates a list of hops that were successfully reached along the path.

Broadcast

the process of sending a packet from one host to all hosts in the network.

Unicast

the process of sending a packet from one host to an individual host.