11.3 Client-Side Network Configuration

IPv6 Format

* An IPv6 address is a 128-bit address made up of 8 16-bit blocks. * Each block is separated by a colon. * Each block is comprised of 4 hexadecimal values between 0000 and FFFF. Each block represents 16 bits of data (FFFF = 1111 1111 1111 1111). * There is approximately 2128 (340 undecillion or 340 trillion trillion) available IPv6 addresses. The specific number of IPv6 addresses is 340,282,366,920,938,463,463,374,607,431,768,211,456

The following are well-known multicast addresses:

* FF02::1 is for all nodes on the local link. This is the equivalent of the IPv4 subnet broadcast address. FF01::1 is for all interfaces on a node. * FF02::2 is for all routers on the local link. FF01::2 is for all routers on node-local. * FF02::1:2 is for all DHCP servers or DHCP relay agents on the local link. DHCP relay agents forward these packets to other subnets. !! There are no broadcast addresses in IPv6. IPv6 uses multicast addresses instead of broadcast addresses.

Because IPv6 addresses are so long, there are rules you can use to simplify an address. These rules are:

* Leading zeros can be omitted in each section. For example, the quartet 0284 could also be written as 284. * An address with consecutive zeros can be expressed more concisely by substituting a double colon for the group of zeros. For example: * FEC0:0000:0000:0000:78CD:1283:F398:23AB * FEC0::78CD:1283:F398:23AB (concise form) !! Removing the zeros and simplifying the address is also known as address compression. You can use address compression only once per address. For example, *FEC2:0000:0000:0000:78CA:0000:0000:23AB can be abbreviated as :FEC2::78CA:0:0:23AB or FEC2:0:0:0:78CA::23AB but not FEC2::78CA::23AB

Because each IP address on any network, including the internet, must be unique, each IP class has a reserved range for private IP addresses.

* Public IP addresses are those that are used on the internet. These are typically assigned by the ISP. * Private IP addresses are used on internal networks only and are not used on the internet. - When a device on the internal network accesses the internet, that data traffic is sent using the public IP address. - Because private IP addresses are never used on the internet, users in one private network can have the same IP address as users in another private network.

To ensure that the interface ID is unique for every host on the network, IPv6 uses the Extended Unique Identifier 64 (EUI-64) format. Following are some details of the EUI-64 format:

* Since each device is hard-wired with a unique 48-bit hardware address called the MAC address, the EUI-64 format uses it to generate a unique interface ID. * The EUI-64 format: 1. Converts the MAC address to binary. 2. Flips the 7th bit from the left (from 1 to 0 or 0 to 1). This bit is called the universal/local (U/L) bit. 3. Inserts the 16-bit hexadecimal value FFFE in the middle. For example, the address for a host with a MAC address of 20-0C-FB-BC-A0-07 would start with the following EUI-64 interface ID: 200C:FBFF:FEBC:A007 The interface ID can also be generated using a special algorithm that generates a completely randomized ID. This guarantees that each device will have a unique ID.

Two methods can be used to configure hosts with IPv4 configurations.

* Static Configuration * Dynamic Configuration

Because IP addresses assigned to hosts must be unique, the use of IP addresses on the internet is controlled by organizations that ensure that every organization is given its own range of IP addresses to assign to hosts:

* The Internet Assigned Numbers Authority (IANA) manages the assignment of IP addresses on the internet. * IANA is operated by the Internet Corporation for Assigned Names and Numbers (ICANN). * IANA allocates blocks of IP addresses to Regional Internet Registries (RIRs). An RIR has authority over IP addresses in a specific region of the world. * An RIR assigns blocks of addresses to internet service providers (ISPs). * An ISP assigns one or more IP addresses to individual computers or organizations connected to the internet.

You are currently learning about networking devices and have just learned about MAC addresses. You look up your device's MAC address, and it comes back as 00-B0-D0-06-BC-AC. Which portion of this MAC address can tell you who the manufacturer is? 00-B0 06-BC-AC BC-AC 00-B0-D0

00-B0-D0 Explanation The first half (first six digits) of a MAC address is assigned to each manufacturer by the Institute of Electrical and Electronic Engineers (IEEE). The rest of the MAC address consists of a unique, randomly generated value.

You have a small home network that uses 192.168.1.0 with the default subnet mask for the network address. The default gateway address is 192.168.1.254, and the router is providing DHCP on the network. The Wrk2 computer has been assigned the IP address of 192.168.1.55. Which of the following is considered the loopback address for the Wrk2 computer? 192.168.1.255 127.0.0.1 192.168.1.0 192.168.1.254 192.168.1.55

127.0.0.1 Explanation 127.0.0.1 is the loopback address for any device. This special address means "this host." If you ping the loopback address, the TCP/IP configuration is tested. A successful test means that TCP/IP is correctly configured on the host. 192.168.1.55 is the current IP address assigned to the host. You can ping this address, but the address is not considered the loopback address. Also, to ping the host's IP address, you must first know the address. Pinging the loopback address always tests the current host regardless of its current IP address. 192.168.1.255 is the broadcast address for the network, meaning any host on the network.

How many bits is an IPv6 address?

128 bits * IPv6 uses 128-bit (2128) addresses, allowing 3.4 x 1038 unique IP addresses. This is equal to 340 trillion trillion trillion IP addresses. IPv6 is written in hexadecimal notation, separated into 8 groups of 16 bits by the colons, thus (8 x 16 = 128) bits in total.

Your Windows workstation has Automatic Private IP Addressing (APIPA) implemented with default settings. Which of the following TCP/IP addresses could you automatically assign to the system, should your DHCP server go down or become inaccessible? 169.254.1.26 10.0.0.65 172.16.1.26 192.168.1.22 168.254.10.25 169.198.1.23

169.254.1.26 Explanation In the event that a DCHP server is not available, Windows workstations can use APIPA to automatically provide themselves with an IP address. The default address range used by APIPA is 169.254.0.1 to 169.254.255.254. Of the options presented, only 169.254.1.26 falls within this range.

Which of the following IP addresses are Class B addresses? (Select three.) 195.155.0.0 64.2.2.64 190.65.2.0 132.12.0.0 129.0.0.0 224.15.55.2 115.33.0.0

190.65.2.0 132.12.0.0 129.0.0.0 Explanation 129.0.0.0, 132.12.0.0, and 190.65.2.0 are Class B addresses. The first octet of a Class B address is in the range of 128 to 191. The first octet of a Class C address is in the range of 192 to 223. The first octet of a Class A address is in the range of 1 to 126.

Which of the following IP addresses have a default subnet mask of 255.255.0.0? (Select three.) 191.168.2.15 123.254.19.6 1.6.45.254 228.62.18.6 168.16.5.1 129.0.0.1

191.168.2.15 168.16.5.1 129.0.0.1 Explanation IP addresses are divided into classes. The most common of these are Classes A, B, and C. Each address class has a different default subnet mask. To identify an IP address's class, look at its first octet. Class A networks use a default subnet mask of 255.0.0.0 and have numbers between 0 and 126 in their first octet. Class B networks use a default subnet mask of 255.255.0.0 and have numbers between 128 and 191 as their first octet. Class C networks use a default subnet mask of 255.255.255.0 and have numbers between 192 and 223 as their first octet. In this question, the IP addresses that fall in the Class B IP address range are 191.168.2.15, 129.0.0.1, and 168.16.5.1.

How many bits is an IPv4 address?

32 bits 4 8-bit octets * The IP protocol identifies each computer connected to the network by its corresponding address * IP numbers can only be zero to 255 or 2^8

Which of the following are valid IPv6 addresses? (Select two.) 343F:1EEE:ACDD:2034:1FF3:5012 6384:1319:7700:7631:446A:5511:8940:2552 A82:5B67:7700:AH0A:446A:779F:FFE3:0091 165.15.78.53.100.1 141:0:0:0:15:0:0:1

6384:1319:7700:7631:446A:5511:8940:2552 141:0:0:0:15:0:0:1 Explanation An IPv6 IP address is a 128-bit address listed as eight 16-bit hexadecimal sections. Leading 0s can be omitted in each section. 6384:1319:7700:7631:446A:5511:8940:2552 is a valid IPv6 IP address. A single set of all-zero sections can be abbreviated with two colons (::). 141::15:0:0:1 would also be a valid way of writing that address. Digits in a hexadecimal system range from 0 to 9 and A to F. H is not a valid hexadecimal number. 343F:1EEE:ACDD:2034:1FF3:5012 is too short, having only six sections instead of eight.

What is an octet?

8 bits

IPv6 address

A 128-bit address made up of eight 16-bit blocks.

IPv4 address

A 32-bit logical address that consists of four decimal numbers separated by a dot that can range from 0 to 255 (ex. 192.168.1.50). * Each decimal number is known as an octet, as it consists of eight 1's and 0's. * The decimal values range from 0-255 because there are 256 (27) combinations of 1's and 0's Composed of two components: * The host ID which is a unique value for each host * The network ID which identifies the network the host is on. All hosts on the network will have the same network ID

MAC address

A 48-bit physical address that is a unique identifier for all network adapters. e.x. 08-71-90-A3-48-F0 08-90 = Manufacturer ID A3-F0 = Randomly Generated Value

Hexadecimal Numbering System

A base-16 number system that consists of the decimal numbers 0-9 and also uses letters A-F to represent values 10-15.

Automatic Private IP Addressing (APIPA)

A feature that allows a device to automatically assign itself an IP address on the 169.254.0.0 network when a DHCP server or manual configuration is unavailable.

Automatic Private IP Addressing (APIPA)169.254.0.0

A feature that allows a device to automatically assign itself an IP address on the 169.254.0.0 network when a DHCP server or manual configuration is unavailable.

Loopback

A type of interface not assigned to a physical port, and which is always up, and sometime used for testing. * local host is 0:0:0:0:0:0:0:1 (also identified as ::1 or ::1/128). * The local loopback address is not assigned to an interface. It can verify that the TCP/IP protocol stack is properly installed on the host.

Anycast address

A unicast address that is assigned to more than one interface, typically belonging to different hosts.

anycast address

A unicast address that is assigned to more than one interface, typically belonging to different hosts. An anycast packet is routed to the nearest interface having that address (based on routing protocol decisions). Details include: * An anycast address is the same as a unicast address. Assigning the same unicast address to more than one interface makes it an anycast address. * A anycast address can be a link-local, unique local, or global unicast address. * When assigning an anycast address to an interface, it must be explicitly identified as an anycast address to distinguish it from a unicast address. * You can use anycast addresses to locate the nearest server of a specific type. For example, the nearest DNS or network time server.

You are working as a junior technician for a small consulting firm. You have been tasked with installing a new computer on the network. You have performed this task and connected the computer to the network. To verify network connectivity, you decide to ping the network server. Before this can happen, the new device needs to know the MAC address of the network server so it can match it to the IP address. The computer sends a broadcast message, asking who has the IP address. The network server responds with its MAC address, and now the computer can communicate with the server. Which protocol is being used when sending the broadcast message to match the MAC address to the IP address? ARP IP ICMP HTTP

ARP Explanation Address Resolution Protocol (ARP) is used to match a device's IP address to its MAC address. Some network devices, such as switches, will build tables to match MAC addresses with IP addresses in order to always know where to send packets to. When a host wants to send some data, it uses ARP to send a broadcast message out on the network, requesting that the host with a specific IP address respond with its MAC address. When the sending host gets the response, it can then match up the MAC address and IP address. Internet Control Message Protocol (ICMP) is used when sending ping packets, but it is not used to match a MAC address to an IP address. HyperText Transfer Protocol (HTTP) defines how pages with hyperlinks (web pages) are designed. It is not used to match a MAC address to an IP address. Internet Protocol (IP) defines how data moves across a network. IP is not used to match the MAC address to an IP address.

multicast address

An IP address representing a selected group of hosts. Packets sent to a multicast address are sent to all interfaces identified by that address. If you use different multicast addresses for different functions, only the devices that need to participate in a particular function will respond to the multicast; devices that do not need to participate in the function will ignore the multicast. * All multicast addresses have an FF00::/8 prefix. * Multicast addresses that are restricted to the local link have an FF02::/16 prefix. Packets starting with FF02 are not forwarded by routers. * Multicast addresses with an FF01::/16 prefix are restricted to a single node.

Unicast address

An address assigned to a single interface for the purpose of allowing one host to send and receive data. Packets sent to a unicast address are delivered to the interface identified by that address.

Multicast address

An address that represents a dynamic group of hosts. Packets sent to a multicast address are sent to all interfaces identified by that address.

unique local unicast address

Are Private addresses used for communication within a site or between a limited number of sites. They are commonly used for network communications that do not cross a public network; they are the equivalent of private addressing in IPv4. * Because unique local addresses are not registered with IANA, they cannot be used on a public network without address translation. * Unique local addresses have an FC00::/7 prefix and include addresses beginning with FC or FD. * Following the prefix, the next 40 bits are used for the Global ID. The Global ID is generated randomly, creating a high probability of uniqueness on the entire internet. * Following the Global ID, the remaining 16 bits in the prefix are used for subnet information. * Unique local addresses are likely to be globally unique, but they are not globally routable. Unique local addresses can be routed between sites by a local ISP. The process for designing a network addressing scheme when using unique local addresses is similar to that used for global unicast addresses. The key difference is how the prefix is defined. Because the address range is not registered, a global routing prefix does not have to be requested from an ISP. Instead, each organization defines its own prefix.

Important

Because the network address and broadcast address reserve the first and last valid IP addresses, usually host IDs don't end in a 0 or 255. But, there are instances where they do.

Binary Numbering System

Binary is the number system that computers and most electronic systems use. Because these systems work on electricity, there are only two states, on and off. This is represented using the numbers 1 and 0.

Binary conversion example

Binary numbers are made of 1.s and 0.s Computers can only read binary. * Used for IPv4 8 bit octet chart 128.64.32.16.8.4.2.1. 66.94.29.13 01000010. = 66 01011110 = 94

CIDR notation

CIDR notation (Classless Inter-Domain Routing) is an alternate method of representing a subnet mask. It is simply a count of the number of network bits (bits that are set to 1) in the subnet mask.

the ipconfig /all command

Command used to display the computer's address including the MAC address.

You are the IT technician for your company. Which of the following mechanisms would BEST allow you to resolve a hostname to its associated IP address? (Select two.) DNS BOOTP DHCP FTP hosts file

DNS hosts file Explanation You can use the Domain Name System (DNS) to get the IP address from a given hostname. You can also use the local hosts file to map hostnames to IP addresses. On Windows systems, this file is located in C:\Windows\system32\drivers\etc\. You use FTP to transfer files. You use either the DHCP protocol or the BOOTP protocol to assign IP addresses and other configuration information to hosts automatically.

Octet

Each number seperated by periods is known as an octet. e.x. 66.94.234.13 has 4 octets

Which values does the hexadecimal numbering system use?

Hexadecimal is the name of the numbering system that is base 16. This system, therefore, has numerals 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15. That means that two-digit decimal numbers 10, 11, 12, 13, 14, and 15 must be represented by a single numeral to exist in this numbering system.

Which of the following correctly describe the most common format for expressing IPv6 addresses? (Select two.) Hexadecimal numbers 32 numbers, grouped using colons Decimal numbers Binary numbers 128 numbers, grouped using colons

Hexadecimal numbers 32 numbers, grouped using colons Explanation IP version 6 addresses are made up of 32 hexadecimal numbers organized into eight quartets. The quartets are separated by colons. An IPv6 address is a 128-bit number (128 binary digits). IP version 4 addresses use decimal numbers organized into four octets and separated by periods.

IPv4 address class

Identifies the range of IP addresses and the default subnet mask used for the range. e.x. 192.168.5.42

link-local unicast address

In TCP/IP version 6, an IP address used for communicating among nodes in the same link and is not allowed on the Internet. Also called local address and link-local address. * Link-local addresses have an FE80::/10 prefix. This includes any address beginning with FE8, FE9, FEA, or FEB. * All nodes must have at least one link-local address, although each interface can have multiple addresses. * Link-local addresses are used for automatic address configuration, for neighbor discovery, or for subnets that have no routers.

What is static configuration?

In a static IP configuration, an onboard network device is assigned an IP address that can be accessed directly from the Internet. It does not receive an IP address from the ICM. Important! You should only assign a static IP address to a secure device, such as a firewall router. The main benefit of static configuration is that the IP configuration does not change. The host retains the IP address even if the device is shut down and rebooted. A static configuration is best used on devices that are accessed by other hosts, such as servers and network printers.

What are 3 types of unicast IPV6 addresses?

Link-local Unique Local Global Unicast

How many IP6 addresses can a device have?

Multiple addresses.

Network ID vs Host ID on a SubnetMask

N= Stays the same for ALL hosts on our network. H = Changes for each one

Logical address

Network addresses assigned by software.

DNS server

On a network, including the internet, computers use IP addresses to identify each other and specify where data should go. However, it is much easier for users to use hostnames to identify websites or other network devices. The DNS server is responsible converting hostnames to IP addresses. Part of the IPv4 configuration is specifying the address of the DNS server.

What is a physical address? Logical address?

Physical Address is the actual address of the data inside the memory. The logical address is a virtual address and the program needs physical memory for its execution. The user never deals with the Physical Address.

Default gateway

Responsible for forwarding data packets to destinations outside of the network. * For example, when a host requests a internet site, the request is sent to the gateway device which then forwards the request to the appropriate destination. When the requested data comes back, the gateway sends it to the requesting host device. * The default gateway is typically a router that sits on the edge of the network. The IPv4 configuration specifies the address of the default gateway.

ping

Send a message from one computer to another to check whether it is reachable and active. * can be used for a DNS server * use netstat -n to check if you're connected

How can an IPv6 address be shortened?

Suppose you enter the IPv6 address 1050:0000:0000:0000:0005:0600:300c:326b, you can omit any leading zeros in the field i.e. Prefix (Network ID): 1050:0000:0000:0000: Interface ID (Host): 0005:0600:300c:326b It abbreviates to 1050::5:600:300c:326b

Decimal Numbering System

The decimal numbering system is the most used number system across the world. Decimal is a base-10 number system that consists of the digits 0,1,2,3,4,5,6,7,8,9.

Prefix

The first 64-bits make up the prefix. or 4^3 * The prefix can be divided into various parts that identify things such as geographic region, the ISP, the network, and the subnet. * The first 48-bits of the address define the site prefix. The site prefix defines the location of the address and is assigned by the local ISP. * The next 16-bits make up the subnet ID. This defines the network the device is connected to. * CIDR notation can be used to indicate the prefix-length. As with an IPv4 address, this shows which portion of the address used for the prefix (network address). - To indicate the prefix length, add a slash (/) followed by the prefix length. - Full quartets with trailing 0s in the prefix address can be omitted (e.g., 2001:0DB8:4898:DAFC::/64). * Because addresses can be allocated based on physical location, the prefix generally identifies the location of the host. The prefix is often referred to as the global routing prefix.

Network*.*.*.0

The first valid IP address on the network is reserved for the network ID. This address is used for routing purposes to identify the network and is not usually assigned to a host.

Which of the following identifies the interface ID component of an IPv6 address? (Select two.) The first four quartets of an IPv6 address. The last 64 bits of an IPv6 address. The last four quartets of an IPv6 address. The last quartet of an IPv6 address. The fourth quartet of an IPv6 address. The first quartet of an IPv6 address.

The last 64 bits of an IPv6 address. The last four quartets of an IPv6 address. Explanation An IPv6 address is a 128-bit binary number that uses the first 64 bits as the address prefix and the last 64 bits of the address as the interface ID. The 128-bit binary number is organized into 32 hexadecimal numbers that are organized further into eight quartets. The last four quartets correspond with the last 64 bits of the IPv6 address.

Broadcast*.*.*.255

The last valid IP address on a network is reserved for broadcast functions. Any packet sent to this address is sent to all devices on the network subnet.

IP addresses have a default class. The address class identifies ____

The range of IP addresses and the default subnet mask used for the range.

Global Unicast Address (GUA)

This is similar to a public IPv4 address. These are globally unique, internet-routable addresses. GUAs can be configured statically or assigned dynamically. The global routing prefix assigned to an organization by an ISP is typically 48 bits long (/48), but it could be as short as /32 or as long as /56, depending on the ISP. All subnet IDs within the same organization must begin with the same global routing prefix; they must be uniquely identified using the value in the subnet field. Using this addressing scheme allows organizations to define a large number (216) of IPv6 subnets. When designing an IPv6 network, you can define the following separate IPv6 subnets: * Network segments separated by routers * VLANs * Point-to-point WAN links

Interface ID

This is the individual host IP portion. It can be assigned to one interface or more than one interface, depending on the type of IPv6 address. The last 64-bits in the address is the interface ID. This is a unique identifier for each device, similar to a MAC address. * Addresses are assigned to interfaces (network connections), not to the host. Technically, the interface ID is not a host address, but is often referred to as the host address. * Interface IDs must be unique within a subnet, but the same interface ID can exist on multiple subnets.

Loopback 127.0.0.1

This special address is also known as home or localhost. This address is reserved by each network interface card (NIC) and is used for testing purposes. Ping requests can be sent to this address and if returned means that the NIC is capable of sending and receiving data packets.

An IPv6 address is divided into ____

Two equal parts. left side: prefix (comparable to network ID in IPv4) right side: interface ID (comparable to host ID in IPv4)

Unicast

Unicast addresses are assigned to a single interface for the purpose of allowing one host to send and receive data. Packets sent to a unicast address are delivered to the interface identified by that address.

Subnet mask

Used to identify the octets in the IPv4 address that are the host ID and those that are the network ID. e.x. 255.255.255.0 255-255 = Network ID 0 = Host ID - Consists of four octets. Each octet is usually either a 0 or 255, but not always. - looks like an IP address - generally has either 255 or 0 in each octet, but not always. - 255 represents the network ID - 0 represents the host ID

Hexadecimal Conversion

Uses both numbers and alphabets. * Using Hexadecimal sys allows for creation of an insane amount of IP addresses * Used for IPv6 (128-bit) hexadecimal address * Each char == 4 bits 4 bit chart 8.4.2.1 0010 = 2 e.x of an IPv6. 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

Dynamic configuration

Uses the Dynamic Host Configuration Protocol (DHCP). This method uses a server that is configured with the network's IP configuration information. * When a new device connects to the network, it sends a broadcast message on the network looking for the DHCP server. * The DHCP server then responds and provides the host with the IPv4 configuration. Using DHCP makes the configuration process much easier as the process is automated once the server has been configured. !! Many SOHO wireless routers have DHCP functionality and can serve as a DHCP server.