SEMESTER 1 Chapter 6 Addressing the Network IPv4 V 4.0

6.1.1

How many bits are the source and destination IPv4 addresses? What is the name for the decimal representation of the binary IP address called? How many bits are there between each “dot”? What are those bits called? Define the network portion of an IP address? What is the host portion of the IP address?

6.1.2 The rest of 6.1 6.2.1

What does the number of bits assigned to host determine? What is the binary range in decimal of a byte? Binary conversions will be covered in the lab meeting? Define a network address.

Define a broadcast address. Define a host address. What is the range where host addresses assigned? 6.2.1.2 What is assigned to determine how many bits are in network bits? Do the number of hosts that can be assigned stay the same when prefix changes? 6.2.2.1 How do you calculate the network value? How do you calculate the first host value? How do you calculate the

32 bits

Dotted Decimal

8 bits Octet a group of hosts that have identical bit patterns in the network address portion of their addresses Although all 32 bits define the IPv4 host address, we have a variable number of bits that are called the host portion of the address the number of hosts that we can have within the network 0-255

Within the IPv4 address range of a network, the lowest address is reserved for the network address. The broadcast address uses the highest address in the network range. The addresses assigned to the end devices in the network. Located between the network and the broadcast address. Prefix

No

All host bits are 0 1 greater than the network address All host bits are turned on

broadcast address? How do you calculate the last host address? 6.2.2.2 This flash exercise is excellent practice for calculating the different values; you can do this until you have mastered the process. Please try it with prefix values of 24 and over so you have an example to go by. 6.2.3 Define unicast Define broadcast Define multicast What is another name for a unicast address? 6.2.3.2 How does a host process a broadcast transmission? What is a broadcast transmission used for?

What are the three examples of broadcast transmissions?

When does a host send a broadcast? How do hosts with the information usually respond to the broadcast? What is a directed broadcast? What is a limited broadcast used for? What forms the boundary for a broadcast domain? 6.2.3.3 What is multicast designed to do? What are the 4 examples of multicast transmissions?

1 less than the broadcast address

the process of sending a packet from one host to an individual host the process of sending a packet from one host to all hosts in the network the process of sending a packet from one host to a selected group of hosts Host address it processes the packet as it would a packet to its unicast address the location of special services/devices for which the address is not known or when a host needs to provide information to all the hosts on the network. Mapping upper layer addresses to lower layer addresses Requesting an address Exchanging routing information by routing protocols When a host needs information, the host sends a request, called a query, to the broadcast address One or more of the hosts with the requested information will respond, typically using unicast. A directed broadcast is sent to all hosts on a specific network. communication that is limited to the hosts on the local network Router conserve the bandwidth of the IPv4 network Video and audio broadcasts Routing information exchange by routing protocols Distribution of software

How are multicast addresses assigned? What is the range for multicast addresses? What is the range for experimental addresses? 6.2.5.1 List the three private address blocks? (This is incredibly important for network administrators to know) What happens if a packet with a private IP address was sent to the Internet? What is NAT Network Address Translation services used for? How does NAT allow a host with a private address to access the Internet? 6.2.5.2 Excellent practice. This is very important for the test. 6.2.6 What is the range for locallink addresses? When is a local link address assigned to a device? 6.2.7

What is the first octet range of Class A? What is the first octet range of Class B? What is the first octet range of Class C? What is the first octet range of Class D? What is the first octet range of Class E? What is the limitation of classful routing? What is the address system used today called? Why should the allocation of addresses inside the networks be planned and documented for the purpose of?

News feeds The multicast clients use services initiated by a client program to subscribe to the multicast group. 224.0.0.0 to 239.255.255.255 240.0.0.0 to 255.255.255.254 10.0.0.0 to 10.255.255.255 (10.0.0.0 /8) 172.16.0.0 to 172.31.255.255 (172.16.0.0 /12) 192.168.0.0 to 192.168.255.255 (192.168.0.0 /16) It would not be forwarded

to translate private addresses to public addresses, hosts on a privately addressed network can have access to resources across the Internet It allows the host to “borrow” a public IP address

169.254.0.0 to 169.254.255.255 automatically assigned to the local host by the operating system in environments where no IP configuration is available 1-126 128-191 192-223 224-239 240-255 wasted many addresses, which exhausted the availability of IPv4 addresses Classless addressing Preventing duplication of addresses Providing and controlling access Monitoring security and performance

What are the different examples of types of hosts?

6.3.1.2 What considerations should be used about where private IP addresses should be used?

6.3.2

Which devices should have static IP addresses assigned? 6.3.2.2 What does DHCP provide for an end device?

6.3.3

6.3.4

6.3.5

6.3.6

What is the block of addresses a DHCP server use called? Which devices should have a static IP address? Why? What does almost all traffic pass through when going between networks? Which IP addresses are used for router interfaces? What is the organization that assigns IP addresses in the US? What are the advantages of having a Tier 1 ISP? What is the focus of a Tier 2 ISP? What is the focus of a Tier 3 ISP? What was the main issue to be addressed by IPv6? What were the other issues that were considered when developing IPv6? List the added features of IPv6.

End devices for users Servers and peripherals Hosts that are accessible from the Internet Intermediary devices Will there be more devices connected to the network than public addresses allocated by the network's ISP? Will the devices need to be accessed from outside the local network? If devices that may be assigned private addresses require access to the Internet, is the network capable of providing a Network Address Translation (NAT) service? printers, servers, and other networking devices that need to be accessible to clients on the network automatic assignment of addressing information such as IP address, subnet mask, default gateway, and other configuration information Address pool

Servers and printers So hosts can have consistent access Intermediary Devices

Lowest or Highest addresses in the range Internet Assigned Numbers Authority (IANA)

reliability and speed focus on business customers The focus of these ISPs is the retail and home markets in a specific locale. Creating expanded addressing capabilities Improved packet handling Increased scalability and longevity QoS mechanisms Integrated security 128-bit hierarchical addressing - to expand addressing capabilities Header format simplification - to improve packet handling Improved support for extensions and options -

6.4.1

6.4.2

6.5

6.5.46 6.6.1

6.6.2

6.6.3

6.6.4

How is the subnet mask created?

What is true if the octet of the subnet mask is 255? What is true if the octet of the subnet mask is 0? What is the result of the ANDing process? What is the only case in which ANDing results in a 1? We will cover this in class. Good exercises and examples to read through. Excellent practice exercises, practice these a lot. What is ping? What happens when the destination host receives an echo request? What is the address to ping the local host? What does a response from the local host tell you? What doesn’t the response from the local host tell you? What does it tell you if a ping to the gateway is successful? What does it tell you if a ping to the remote host is successful?

What does the traceroute utility do? Define Round Trip Time (RTT). Define Time to Live (TTL).

for increased scalability/longevity and improved packet handling Flow labeling capability - as QoS mechanisms Authentication and privacy capabilities - to integrate security by placing a binary 1 in each bit position that represents the network portion and placing a binary 0 in each bit position that represents the host portion All of the octet is network/subnetwork bits. All of the octet is host bits. The network address 1 anded with a 1

utility for testing IP connectivity between hosts it responds with an ICMP Echo Reply datagram. 127.0.0.1 that IP is properly installed on the host an indication that the addresses, masks, or gateways are properly configured indicates that the host and the router's interface serving as that gateway are both operational on the local network It means that we have verified our host's communication on the local network, the operation of the router serving as our gateway, and all other routers that might be in the path between our network and the network of the remote host. allows us to observe the path between these hosts the time a packet takes to reach the remote host and for the response from the host to return When a packet enters a router, the TTL field is

6.6.5

decremented by 1. When the TTL reaches zero, a router will not forward the packet and the packet is dropped. What does ICMP provide for ICMP provides control and error messages the TCP/IP protocol stack? and is used by the ping and traceroute utilities. List the 5 ICMP messages Host conformation that may be sent? Unreachable Destination or Service Time exceeded Route redirection Source quench What are the 4 destination 0 = net unreachable unreachable codes listed? 1 = host unreachable 2 = protocol unreachable 3 = port unreachable

You will use the following tables for multiple questions. * 255.255.255.192 (or /26) 0 - 63 64 - 127 128 - 191 192 - 255 (with multiplier of 64) * 255.255.255.224 (or /27) 0 - 31 32 - 63 64 - 95 96 - 127 128 - 159 160 - 191 192 - 223 224 - 255 (with multiplier of 32) * 255.255.255.240 (or /28) 0 - 15 16 - 31 32 - 47 48 - 63 64 - 79 80 - 95 96 - 111 112 - 127 And so on (with multiplier of 16) * 255.255.255.248 (or /29) 0 - 7 8 - 15 16 - 23 24 - 31 32 - 39 40 - 47 48 - 55 56 - 63 And so on (with multiplier of 8)

* Which prefix (subnetmask) needed for the following network? (Hint: you need to know the block size.)

- Use the reference table to solve this problem. * You will be presented a list of IP address and are expected to pick up: - Usable (assignable) host addresses * Study the reference table included above. - Network IP address * Study the reference table included above. - Broadcast IP address * Study the reference table included above. * Network IP address - The IPv4 host address is logically ANDed with its subnet mask to determine the network address to which the host is associated. - At Layer 3, we define a network as a group of hosts that have identical bit patterns in the network address portion of their addresses. - A router uses this address forwarding of packet to a given destination - Network address varies in length - portion of the high-order bits (1) represents the network address.

* Some basic rule about IP address:  Private addresses – There are blocks of addresses that require no Internet access. • 10.0.0.0 to 10.255.255.255 (10.0.0.0 /8) • 172.16.0.0 to 172.31.255.255 (172.16.0.0 /12) • 192.168.0.0 to 192.168.255.255 (192.168.0.0 /16) 

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If devices that may be assigned private addresses require access to the Internet, a NAT service would allow those devices with private addresses to effectively share the remaining public addresses.

Loopback – The loopback address 127.0.0.1. – You can ping the loopback address to test the configuration of TCP/IP on the local host. – This also covers all addresses in 127.0.0.0 to 127.255.255.255.

* You will be asked to troubleshooting of why is your PC not able to get on the internet. - You need to make sure that the IP address for your PC, your default gateway and router interface are all in the same subnet. - Study the reference table included above.

* 255.255.0.0: How many hosts are in this subnet? * 255.255.255.0: How many hosts are in this subnet? * 255.255.254.0: How many hosts are in this subnet? * 255.255.248.0: How many hosts are in this subnet? * With a static assignment, the network administrator must manually configure the network information for a host  The addresses for these devices should be static. – Addresses for Servers and Peripherals – Addresses for Hosts that are Accessible from Internet – The router or firewall * IPv6 offers: – 128-bit hierarchical addressing - to expand addressing capabilities – Header format simplification - to improve packet handling – Improved support for extensions and options - for increased scalability/longevity and improved packet handling – Flow labeling capability - as QoS mechanisms – Authentication and privacy capabilities - to integrate security * IPv6 is not a new Layer 3 protocol – it is a new protocol suite. – New messaging protocol (ICMPv6) – New routing protocols. – don’t pick the answer for faster routing protocol lookup * Time to Live (TTL) – Traceroute makes use of a function of the TTL field in the Layer 3 header and ICMP Time Exceeded Message. – When a packet enters a router, the TTL field is decremented by 1. When the TTL reaches zero, a router will not forward the packet and the packet is dropped. – In addition to dropping the packet, the router normally sends an ICMP Time Exceeded message addressed to the originating host. This ICMP message will contain the IP address of the router that responded. * Pinging the Local Loopback  One case is for testing the internal configuration of IP on the local host.  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.

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This response is not, however, an indication that the addresses, masks, or gateways are properly configured. Nor does it indicate anything about the status of the lower layer of the network stack.