Unit 2 IPv4 Addressing

169.254.0.0 to 169.254.255.255

APIPA / link-local autoconfiguration. This range is used by hosts for autoconfiguration (selecting a link-local address). The first 256 addresses and last 256 addresses should not be used by hosts though.

Class E addresses

(240.0.0.0 through 255.255.255.255) are reserved for experimental use and testing

Class D addresses

(244.0.0.0 through 239.255.255.255) are used for multicasting

Quality of Service

A separate class of multicast routing protocols (Distance Vector Multicast Routing Protocol [DVMRP], Protocol Independent Multicast [PIM], Multicast Border Gateway Protocol [MBGP], or Multiprotocol Label Switching [MPLS]) manage forwarding and ___.

binary

Alternatively, rather than worry about different address class ranges , just remember the rule that all class A networks start with ____ 0, all class B start with a ___ 10, and class C start with a ___ 110.

data link

At the ___ layer, multicasts are delivered using a specially designed OUI belonging to IANA [01:00:5E] in the MAC address.

10.0.0.0 to 10.255.255.255

Class A private address range

172.16.0.0 to 172.31.255.255

Class B private address range

192.168.0.0 to 192.168.255.255

Class C private address range

domains

Collision ____ are no longer a performance barrier, but broadcast ____ can be.

hosts

Excessive broadcast traffic is created when there are more ___ on the same network.

propagate

IGMP is only used to configure group membership and ___ that information between multicast routers.

VLANs

If ___ are implemented, the broadcast domain will normally be restricted to interface connected to the same VLAN. This does mean that users attached to different switches (but the same VLAN) can be in the same broadcast domain.

subnets

If a VLAN contains multiple ___, nodes will receive broadcast traffic for all the ____. This would be a very complex configuration however. Normally the network would be designed with a 1:1 mapping between VLANs and subnets.

broadcast

If every port on a switch is in the same ___ domain, this can lead to a large amount of broadcast traffic, making the network inefficient.

broadcast, multicast

If the local host needs to communicate with multiple hosts, it can do so either by using a ____, in which the destination address is all hosts on the local network, or else by using a ____ address, which represents a group of computers, programmed to respond to a particular address.

classless

In a ___ scheme, the network ID does not depend on the class of the IP address number but on the number of bits set to 1 in an associated network prefix.

classless scheme

In a ____, the idea that the netmask should align along a particular octet boundary has been discarded completely.

Ethernet

In early ___ (using hubs to connect nodes), unicast and broadcast traffic was received by every node attached to a hub. The nodes are all in the same collision domain.

WAN

Many organizations have more than one site and WAN links between them. The ___ link normally forms a separate network.

2

Recall that at layer __ is also the concept of a collision domain.

broadcast

Routers do not forward ___ packets. At layer 2, ___ are delivered using the "group" MAC address (ff:ff:ff:ff:ff:ff)

bits

Supernetting is described in RFC 4632. Essentially, it uses bits normally assigned to the network ID to mask them as host or subnet bits.

Class C network

Support only 254 hosts each, but there are over 2 million of them.

traffic

Switches capable of recognizing IGMP ____ ("IGMP snooping") are also beneficial otherwise the traffic is broadcast to all hosts.

1

The broadcast address of a network is one where the host bits are all set to __.

network ID, host ID

The combination of an IP address and subnet mask can be used to describe a ____ and a ___. These parameters allow an internetwork to be divided into logically separate networks and each network to be divided into subnetworks (or subnets)/

IP address

The default masks comprise whole octets. These default masks can be modified to allow a single network to be divided into a number of subnets. To do this, additional bits of the ___ have to be allocated to the network address rather than the host ID.

IGMP

The original version of ____ (RFC 1112) defines two messages: a query message sent by routers (queriers) and a report message sent by hosts.

Class B network

There are 16 thousand ___, each containing up to about 65.000 hosts.

switches

With ____, each port is in its own collision domain. This makes the concept of a collision domain somewhat redundant for wired Ethernet using switches.

unicast

When an IPv4 host wants to send a packet to another single host, it uses a ___ packet, addressed to the destination host.

IP address

When considering classful addressing, it is important to be able to identify the address class from the first octet of the ____.

default mask

When subnetting, the whole network is still referred to by the network ID (by routers external to the network) and the ____: 172.16.0.0 / 255.255.0.0 for example.

IGMPv2 (RFC 2236)

adds the option for a host to explicitly leave a multicast group; the router then queries whether there are any members left in the group.

IGMPv3 (RFC 3376)

adds the option to select from different sources when determining group membership.

classful addressing scheme

allocates the network ID based on the first octet of the IP address. The network IDs are divided into three classes, defining different sizes of network.

Multicasting

allows one computer on the internet (or private network) to send content to multiple other computers that have identified themselves as interested in receiving the originating computer's content (that have joined a multicast group)

Addressing schemes

describes different ways of configuring IP addressing to suit different types and sizes of networks.

Internet Group Management Protocol (IGMP)

is an internet protocol, operating at the network layer that provides a way for an IP host to report its multicast group membership to adjacent routers.

Multicast

must take place using specially configured routers and protocols. This type of address represents a group of programmed computers

devices

network ____ between the client group and multicast server must all be IGMP-compatible (including routers, switches, and network cards)

subnetting

replaced the idea of a classful IP address with one associated with a subnet mask in 1985.

default

the ___ subnet masks correspond to the three classes of unicast IP address (A, B, and C)

Class A network

these class of addresses support large numbers of hosts - over 16 million. However there are only 126 of them.

broadcast domain

this is where all the hosts receive the same broadcast packets. The boundaries of this domain are established at the network layer (layer 3) by routers.

private addressing scheme

typically used to allocate IP addresses to hosts. These addresses can be drawn from one of the pool of addresses defined in RFC 1918 as non-routable over the internet.

Network Address Translation

used by the router to translate between the private and public addresses

Supernetting

was designed to solve two major problems of the classful addressing scheme as more and more networks joined the network through the early 1990s. The first was that network addresses were becoming very scarce and the second was near exponential growth in internet routing tables.

classful addressing scheme

was employed in the 1980s, before the use of subnet masks to identify the network ID portion of an address became widespread.