1

CAPS 1145 – Introduction to Networks (Course Handout)

7. Application: Point of contact for all network aware application. 6. Presentation: Gentrify the data (converted) 5. Session: Creates and maintains Sessions. 4. Transport: Reliable (TCP) packet verification, Unreliable (UDP) live no, verification, Port Numbers = socket, creates a port # 3. Network: header – Data Unit: Packet layer finds IP address 2. Data Link: data link = Frame, MAC address (error checking layer) 1. Physical: Data transfer occurs (Bits) Wires.

Physical Layer Encoding Source Node Destination Node

(Protocol Data Units) Encapsulation

PDU PDU

Data

Segment

Packet

Frame

Bits

Application

Presentation

Session

Transport

Network

Data Link

Physical

Application

Presentation

Session

Transport

Network

Data Link

Physical

Data

Segment

Packet

Frame

Bits

Application Data

Data Data Data

Network Header

Data

Frame Trailer Header

Data Network Header

Frame Header

1 0 1 0 0 1 1 1 0 1 0

Bits

2

OSI Layers

Function

Data Type

Protocols

Network Components

Application

User Application services, Allows access to network services that support Applications. Handles network access, Flow control and error recovery.

User DSN, DHCP, FTP, HTTPS, IMAP, LDAP, NNTP, NTP, POP3, RMON, RTP, RTSP, SSH, SIP, SMTP, SNMP, Telnet, TFTP.

Gateway

Presentation

Data Translation; Compression and Encryption.

Encoded JPEG, MIDI, MPEG, PICT, TIFF, SSL, Shells and Redirectors, MIME.

Gateway, Redirector.

Session

Session Establishment, Management and Termination.

Session NetBIOS, NFS, PAP, SCP, Sockets, Named Pipes, SQL, RPC, ZIP.

Gateway

Transport

Additional connection below the session layer. Manages the flow control of data between users across the Network. Provides error-handling.

Datagram’s / Segments

TCP and UDP, SPX, NetBUEI/NBF

Gateway, Advanced Cable Tester, Brouter.

Network

Translates logical network addresses and MAC addresses. Logical Addressing; Routing; Datagram; Encapsulation; Fragmentation and Reassembly; Error Handling and Diagnostics.

Datagram’s / Packets

DLC, ICMP, IGMP, IP, IPv4, IPv6, IPX, IP NAT, IPsec, Mobil IP, RIP and BGP.

Brouter, Router, Frame Relay Devices, ATM Switch, Advanced Cable Tester.

Data link

Handles data frames between the Network and Physical Layers. The receiving end packages, raw data from the Physical layer into data frames for delivery to the Network layer. Logical Link Control; Media Access Control; Data Framing; Addressing Error Detection and Handling. Defining requirements of the Physical layer.

Frames ARP, ATM, CDP, CDDI, FDDI, Frame Relay, HDLC, MPLS, PPP, STP, SLIP and Token Ring

Bridge, Switch, ISDN Router, Intelligent Hub, NIC, Advanced Cable Tester.

Physical

Transmits raw bit stream over physical cable, defines cables, cards, and all physical aspects. Defines NIC attachments to hardware, how cable is attached to the NIC card. Encoding and Signaling; Physical Data Transmission; Hardware Specifications; Topology and Design.

Bits Bluetooth, Ethernet, DSL, ISDN, 802.11 WiFi.

Repeater, Multiplexer, Hubs, TDR, Oscilloscope Amplify.

3

Initializing and Reloading a Router and Switch

Topology

Set Up Devices in the Network as Shown in the Topology

Attach console cables to the devices shown in the topology diagram.

Power on all the devices in the topology.

Wait for all devices to finish the software load process before moving to Part 2.

Initialize the Router and Reload

Initialize the Router and Reload

Step 1: Connect to the router.

Enter privileged EXEC mode using the enable command.

Router> enable

Router#

Step 2: Erase the startup configuration file from NVRAM.

Type the erase startup-config command to remove the startup configuration from nonvolatile random-access memory (NVRAM).

Router# erase startup-config

Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]

[OK]

Erase of nvram: complete

Router#

Step 3: Reload the router.

Issue the reload command to remove an old configuration from memory. When prompted to Proceed with reload, press Enter to confirm the reload. Pressing any other key will abort the reload.

Router# reload

Proceed with reload? [confirm]

*Nov 29 18:28:09.923: %SYS-5-RELOAD: Reload requested by console. Reload Reason:

Reload Command.

4

Note: You may receive a prompt to save the running configuration prior to reloading the router. Respond by typing no and press Enter.

System configuration has been modified. Save? [yes/no]: no

Step 4: Bypass the initial configuration dialog.

After the router reloads, you are prompted to enter the initial configuration dialog. Enter no and press Enter.

Would you like to enter the initial configuration dialog? [yes/no]: no

Step 5: Terminate the autoinstall program.

You will be prompted to terminate the autoinstall program. Respond yes and then press Enter.

Would you like to terminate autoinstall? [yes]: yes

Router>

Part 2: Initialize the Switch and Reload

Step 1: Connect to the switch.

Console into the switch and enter privileged EXEC mode.

Switch> enable

Switch#

Step 2: Determine if there have been any virtual local-area networks (VLANs) created.

Use the show flash command to determine if any VLANs have been created on the switch.

Switch# show flash

Directory of flash:/

2 -rwx 1919 Mar 1 1993 00:06:33 +00:00 private-config.text

3 -rwx 1632 Mar 1 1993 00:06:33 +00:00 config.text

4 -rwx 13336 Mar 1 1993 00:06:33 +00:00 multiple-fs

5 -rwx 11607161 Mar 1 1993 02:37:06 +00:00 c2960-lanbasek9-mz.150-2.SE.bin

6 -rwx 616 Mar 1 1993 00:07:13 +00:00 vlan.dat

32514048 bytes total (20886528 bytes free)

Switch#

Step 3: Delete the VLAN file.

a. If the vlan.dat file was found in flash, then delete this file.

Switch# delete vlan.dat

Delete filename [vlan.dat]?

You will be prompted to verify the file name. At this point, you can change the file name or just press Enter if you have entered the name correctly.

b. When you are prompted to delete this file, press Enter to confirm the deletion. (Pressing any other key will abort the deletion.)

Delete flash:/vlan.dat? [confirm]

Switch#

5

Step 4: Erase the startup configuration file.

Use the erase startup-config command to erase the startup configuration file from NVRAM. When you are prompted to remove the configuration file, press Enter to confirm the erase. (Pressing any other key will abort the operation.)

Switch# erase startup-config

Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]

[OK]

Erase of nvram: complete

Switch#

Step 5: Reload the switch.

Reload the switch to remove any old configuration information from memory. When you are prompted to reload the switch, press Enter to proceed with the reload. (Pressing any other key will abort the reload.)

Switch# reload

Proceed with reload? [confirm]

Note: You may receive a prompt to save the running configuration prior to reloading the switch. Type no and press Enter.

System configuration has been modified. Save? [yes/no]: no

Step 6: Bypass the initial configuration dialog.

After the switch reloads, you should see a prompt to enter the initial configuration dialog. Type no at the prompt and press Enter.

Would you like to enter the initial configuration dialog? [yes/no]: no

Switch>

Configuring a Switch Management Address

Topology

Part 1: Addressing Table

Device Interface IP Address Subnet Mask

S1 VLAN 1 192.168.1.2 255.255.255.0

PC-A NIC 192.168.1.10 255.255.255.0

Part 2: Objectives

Part 1: Configure a Basic Network Device

Part 2: Verify and Test Network Connectivity

6

Part 1: Configure a Basic Network Device

In Part 1, you will set up the network and configure basic settings, such as hostnames, interface IP addresses, and passwords.

Step 1: Cable the network.

a. Cable the network as shown in the topology.

b. Establish a console connection to the switch from PC-A.

Step 2: Configure basic switch settings.

In this step, you will configure basic switch settings, such as hostname, and configure an IP address for the SVI. Assigning an IP address on the switch is only the first step. As the network administrator, you must specify how the switch will be managed. Telnet and SSH are two of the most common management methods. However, Telnet is a very insecure protocol. All information flowing between the two devices is sent in plaintext. Passwords and other sensitive information can be easily viewed if captured by a packet sniffer.

a. Assuming the switch did not have a configuration file stored in NVRAM, you will be at the user EXEC

mode prompt on the switch. The prompt will be Switch>. Enter privileged EXEC mode.

Switch> enable

Switch#

b. Use the privileged EXEC show running-config command to verify a clean configuration file. If a configuration file was previously saved, it will have to be removed. Depending on the switch model and IOS version, your configuration may look slightly different. However, there should not be any configured passwords or IP address set. If your switch does not have a default configuration, ask your instructor for help.

c. Enter global configuration mode and assign the switch hostname.

Switch# configure terminal

Switch(config)# hostname S1

S1(config)#

d. Configure the switch password access.

S1(config)# enable secret class

S1(config)#

e. Prevent unwanted DNS lookups.

S1(config)# no ip domain-lookup

S1(config)#

f. Configure a login MOTD banner.

S1(config)# banner motd #

Enter Text message. End with the character ‘#’.

Unauthorized access is strictly prohibited. #

g. Verify your access setting by moving between modes.

S1(config)# exit

S1#

S1# exit

Unauthorized access is strictly prohibited.

S1>

7

IPv4 IP addressing: 32 bit Octet Total = 255

128 64 32 16 8 4 2 1

1 1 0 0 0 0 0 0

128 + 64 = 192

IP address: 11000000.10101000.01100100.11100001 = 192.168.100.225 A B C Host part Subnet Mask: 11111111.11111111.11111111. 00000000 = 255.255.255.0 Ones stops here Gateway: 192.168.100.1 A – Stops after 1st octect Network ID Host part B – Stops after 2nd octect C – Stops after 3rd octect First Last Network ID = 192.168.100.0 Broadcast ID = 192.168.100.255 Classes: A = 1-126 2^24 - 2 = 16,777,216 (valid IP addresses)

B = 128-191 2^16 - 2 = 1,048,576 (valid IP addresses) C = 192-223 2^8 - 2 = 65,536 (valid IP addresses) D = 224-239

E = 240-255 127 is skipped used for loop back

Class C Subnetting Private: Local Network only Public: Internet access

Class A – 10.0.0.0 / 10.255.255.255 Class B – 172.16.0.0 / 171.30.255.255 Class C – 192.168.0.0 / 192.168.255.255

Class C: /24+ IP Address: 192.168.100.225 11000000.10101000.11000100.11100001 Subnet Mask: 255.255.255.0 11111111.11111111.11111111.00000000 7 128 - 2 Subnetting: 255.255.255.10000000 Split network in 2 (2^7 – 2 = 126) Hosts 2^7 2^6 2^5 2^4 2^3 2^2

128 64 32 16 8 4

2 4 8 16 32 64 Using: 255.255.255.10000000 (128) Block Size Network ID 1 = 192.168.100.0 Broadcast ID = 192. 168.100.127

Network ID 2 = 192.168.100.128 Broadcast ID = 192.168.100.255

Using: 255.255.255.11000000 (64) Block Size Network ID 1 = 192.168.100.0 Broadcast ID = 192.168.100.63 Broadcast is one less than next Network ID Network ID 2 = 192.168.100.64 Broadcast ID = 192.168.100.127 Network ID 3 = 192.168.100.128 Broadcast ID = 192.168.100.191 Network ID 4 = 192.168.100.192

8

Broadcast ID = 192.168.100.255

Borrowed Bits 1 2 3 4 5 6

Mask Value 128 192 224 240 248 252

Subnetts 2 4 8 16 32 64

Hosts 126 62 30 14 6 2

CIDR /25 /26 /27 /28 /29 /30

Block Size 128 64 32 16 8 4

Requirements:

1) Create 3 sub-networks 2) Use a Class C IP address: 192.168.1.0 3) Determine the Network Id and Broadcast Id of all the subnets

CIDR

/25 /26 /27 /28 /29 /30 /31 /32 Slash Notation

128 64 32 16 8 4 2 1

1 1 0 0 0 0 0 0

2 4 8 16 32 64

128 192 224 240 248 252 254 255

64 – 2 = 62 Bc .255 .0 Network (Nw) (Ha) .193-.254 .1-.62 Usable Host address (Ha) .192 (Nw) .63 Broadcast (Bc)

Bc.191 .64 (Nw) .129-.190 .65-.126 Usable Host addresses (Ha) .128 (Nw) .127 Broadcast

Requirements: Find the Network Id and Broadcast Id of this IP address: 192.168. 5.0 /26 Create: 60 hosts and 30 hosts /1 /2 /3 /4 /5 /6 /7 /8 /9 /10 /11/12/13/14/15/16 /17/18/19/20/21/22/23/24 /25/26/27/28/29/30/31/32

1 1 0 0 0 0 0 0 . 1 0 1 0 1 0 0 0 . 0 0 0 0 0 1 0 1 . _ _ _ _ _ _ _ _

8,3

88

,60

8

4,1

94

,30

4

2,0

97

,15

1

1,0

48

,57

6

52

4,2

88

26

2,1

44

13

1,0

72

65

,53

6

32

,76

8

16

,38

4

8,1

92

4,0

96

2,0

48

1,0

24

51

2

25

6

12

8

64

32

16

8

4

2

1

Host SubNet Host Range Broadcast SubNetMask Slash Notation

62 .0 .1 - .62 .63 255.255.255.192 /26

30 .64 .65 - .94 .95 255.255.255.224 /27

14 .96 .97 - .110 .111 255.255.255.240 /28

6 .112 .113 - .118 .119 255.255.255.248 /29

2 .120 .121 - .122 .123 255.255.255.252 /30

62 Hosts 62 Hosts

62 Hosts 62 Hosts

9

SubNet Masks:

128.0.0.0 /1 192.0.0.0 /2 224.0.0.0 /3 240.0.0.0 /4 248.0.0.0 /5 252.0.0.0 /6 254.0.0.0 /7 255.0.0.0 /8

255.128.0.0 /9 255.192.0.0 /10 255.224.0.0 /11 255.240.0.0 /12 255.248.0.0 /13 255.252.0.0 /14 255.254.0.0 /15 255.255.0.0 /16

255.255.128.0 /17 255.255.192.0 /18 255.255.224.0 /19 255.255.240.0 /20 255.255.248.0 /21 255.255.252.0 /22 255.255.254.0 /23 255.255.255.0 /24

255.255.255.128 /25 255.255.255.192 /26 255.255.255.224 /27 255.255.255.240 /28 255.255.255.248 /29 255.255.255.252 /30 255.255.255.254 /31 255.255.255.255 /32

Binary to Hexadecimal

Simplified Method: 8 4 2 1 8 4 2 1

0101/0111 Octet split in two

5 7 0000 = 0 0001 = 1 0010 = 2 0011 = 3 0100 = 4

0101 = 5 0110 = 6 0111 = 7 1000 = 8 1001 = 9

1010 = A (10) 1011 = B (11) 1100 = C (12) 1101 = D (13) 1110 = E (14) 1111 = F (15)

Convert the following IP Address to Hexadecimal: 192.168.100.225 192 168 100 225 128 64 32 16 8 4 2 1 . 128 64 32 16 8 4 2 1 . 128 64 32 16 8 4 2 1 . 128 64 32 16 8 4 2 1

1 1 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 1 1 0 0 1 0 0 1 1 1 0 0 0 0 1 8 4 2 1 / 8 4 2 1 / 8 4 2 1 / 8 4 2 1 / 8 4 2 1 / 8 4 2 1 / 8 4 2 1 / 8 4 2 1

C 0 A 8 6 4 E 1

10

Class C Subnetting

Addresses Host Netmask Networks

/30 4 2 255.255.255.252 64

/29 8 6 255.255.255.248 32

/28 16 14 255.255.255.240 16

/27 32 30 255.255.255.224 8

/26 64 62 255.255.255.192 4

/25 128 126 255.255.255.128 2

/24 256 254 255.255.255.0 1 8 - 2 = 6 /29 8 / 256 = 32

/23 512 510 255.255.254.0 2 Network Host Broadcast

/22 1,024 1022 255.255.252.0 4 0 1 6 7

/21 2,048 2046 255.255.248.0 8 8 9 14 15

/20 4,096 4094 255.255.240.0 16 16 17 22 23

/19 8,192 8190 255.255.224.0 32 24 25 30 31

/18 16,384 16382 255.255.192.0 64 32 33 38 39

/17 32,768 32766 255.255.128.0 128 40 41 46 47

/16 65,536 65534 255.255.0.0 256 48 49 54 55

56 57 62 63

128 - 2 = 126 /25 128 / 256 = 2 16 - 2 = 14 /28 16 / 256 = 16 64 65 70 71

Network Hosts Broadcast Network Host Broadcast 72 73 78 79

0 1 126 127 0 1 14 15 80 81 86 87

128 129 254 255 16 17 30 31 88 89 94 95

32 33 46 47 96 97 102 103

48 49 62 63 104 105 110 111

64 - 2 = 62 /26 64 / 256 = 4 64 65 78 79 112 113 118 119

Network Host Broadcast 80 81 94 95 120 121 226 127

0 1 62 63 96 97 110 111 128 129 134 135

64 65 126 127 112 113 126 127 136 137 142 143

128 129 190 191 128 129 142 143 144 145 150 151

192 193 254 255 144 145 158 159 152 153 158 159

160 161 174 175 160 161 166 167

176 177 190 191 168 169 174 175

32 - 2 = 30 /27 32 / 256 = 8 192 193 206 207 176 177 182 183

Network Host Broadcast 208 209 222 223 184 185 190 191

0 1 30 31 224 225 238 239 192 193 198 199

32 33 62 63 240 241 254 255 200 201 206 207

64 65 94 95 208 209 214 215

96 97 126 127 216 217 222 223

128 129 158 159 224 225 230 231

160 161 190 191 232 233 238 239

192 193 222 223 240 241 246 247

224 225 254 255 248 249 254 255

11

Class B Subnetting:

B C

128 64 32 16 8 4 2 1 • 128 + 64 32 16 8 4 2 1

• • • • • • • • • • • • • • • •

Netwrk-2 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16,384 32,768 65,536

Host-2 65,536 32,768 16,384 8,192 4,096 2,048 1,024 512 256 128 64 32 16 8 4 2

CIDR /17 /18 /19 /20 /21 /22 /23 /24 /25 /26 /27 /28 /29 /30 /31 /32

If IP = 172.16.0.0 and I need 1,000 Networks / Subnet mask = 128 + 64 255.255.255.192 /26

Increment by 64 up to 192, then increment 172.16.0.0 by one and continue the series.

Remember Network always start with 0, Host 1- always end with Host 254, Broadcast 255.

0

64

128

192

0

64

128

192

0

64

128

192

Network Range Broadcast

172.16.0.0 172.16.0.1 – 172.16.0.62 172.16.0.63

172.16.0.64 172.16.0.65 – 172.16.0.126 172.16.0.127

172.16.0.128 172.16.0.129 – 172.16.0.190 172.16.0.191

172.16.0.192 172.16.0.193 – 172.16.0.254 172.16.0.255

172.16.1.0 172.16.1.1 – 172.16.1.62 172.16.1.63

172.16.1.64 172.16.1.65 – 172.16.1.126 172.16.1.127

172.16.1.128 172.16.1.129– 172.16.0.190 172.16.1.191

172.16.1.192 172.16.1.193 – 172.16.1.254 172.16.1.255

172.16.2.0 172.16.2.1 – 172.16.2.62 172.16.2.63

172.16.2.64 172.16.2.65 – 172.16.2.126 172.16.2.127

172.16.2.128 172.16.2.129 – 172.16.2.190 172.16.2.191

172.16.2.192 172.16.2.193 – 172.16.2.254 172.16.2.255

0 172.16.3.0 172.16.3.1 – 172.16.3.62 172.16.3.63

64 172.16.3.64 172.16.3.65 – 172.16.3.126 172.16.3.127

128 172.16.3.128 172.16.3.129 – 172.16.3.190 172.16.3.191

192 172.16.3.192 172.16.3.193 – 172.16.3.254 172.16.3.255

12

Class B Subnetting (Cont.) Subnetting a Class B network you will be using the third octect; in a Class C we worked with the fouth octect. Look at this:

To enable you to subnet a Class B, use the same subnet numbers for the third octect as in a Class C. You will need to add a zero (0) to the network portion and a 255 to the broadcast section in the fourth octect. A class B network address has 16 bits available for host addressing (14 bits for subnetting, 2 bits for host addressing). Example 1

Given the network address: 172.16.0.0 /20 /17 /18 /19 /20 /21 /22 /23 /24

128 64 32 16 8 4 2 1 + + + =

From the above network IP address, the mask will be 255.255.240.0 which means we are using the bit value or a block size of 16. We are going to subnet it for three different networks with equal host IP addresses; remember we are working on the THIRD octect with the block size of 16. Network A Network address: 172.16.16.0

First Host address: 172.16.16.1

Last host address: 172.16.31.254

Broadcast address: 172.16.31.255

We add the bit block size again (16+16=32) to obtain the next network address which is 172.16.32.0

Network B Network address: 172.16.32.0

First Host address: 172.16.32.1

Last host address: 172.16.47.254

Broadcast address: 172.16.47.255

We add the bit block size again to get the next network address (32+16=48) Network C Network address: 172.16.48.0

First Host address: 172.16.48.1

Last host address: 172.16.63.254

Broadcast address: 172.16.63.255

Same addition before for the next network. We add the bit block size again to get the next network address (48+16=64)

13

WAN 1

Connection from Router A to Router B

Network address: 172.16.64.0

Network A to B address: 172.16.64.1 255.255.252.0

Network B to A address: 172.16.64.2 255.255.252.0

The next network will have a 4 bits value added to the last network; (64+4=68) WAN 2

Connections from Router A to Router C

Network address: 172.16.68.0

Network A to C address: 172.16.68.1 255.255.252.0

Network C to A address: 172.16.68.2 255.255.252.0

There are different ways to subnet; you have to device a way to make it simple for yourself! Let’s apply it to a Topology:

Router A: RA(config)#interface fa0/0

RA(config-if)#ip address 172.16.16.1 255.255.240.0

RA(config-if)#no shutdown

RA(config-if)#exit

RA(config)#interface se0/0/0

RA(config-if)#ip address 172.16.64.1 255.255.252.0

RA(config-if)#no shutdown

RA(config-if)#exit

RA(config)#interface se0/0/1

RA(config-if)#ip address 172.16.68.1 255.255.252.0

RA(config-if)#no shutdown

RA(config-if)#exit

14

Router B

RB#config t

RB(config)#interface fa0/0

RB(config-if)#ip address 172.16.32.1 255.255.240.0

RB(config-if)#no shutdown

RB(config-if)#exit

RB(config)#interface se0/0/0

RB(config-if)#ip address 172.16.64.2 255.255.252.0

RB(config-if)#no shutdown

RB(config-if)#exit

Router C

RC#config t

RC(config)#interface fa0/0

RC(config-if)#ip address 172.16.48.1 255.255.240.0

RC(config-if)#no shutdown

RC(config-if)#exit

RC(config)#interface se0/0/0

RC(config-if)#ip address 172.16.68.2 255.255.252.0

RC(config-if)#no shutdown

RC(config-if)#exit

Ping from Network RA to RB networks will work.

15

IPv6 Address format: X:X:X:X:X:X:X:X /64 Each X = 4 Hex values (Hexa = 16bits). 48bits 16 64bits

FC 99 47 75 CE E0

1111 1100 1001 1001 0100 0111 0111 0101 1100 1110 1110 0000

1111 1100 1001 1001 0100 0111 1111 1111 1111 1110 0111 0101 1100 1110 1110 0000

Insert FF FE

1111 1110 1001 1001 0100 0111 1111 1111 1111 1110 0111 0101 1100 1110 1110 0000

FE 99 47 1111 1111 1111 1110 75 CE E0

IPv6 Address Types

Address Type Description

Unicast One to One (Global, Link local, Site local) An address destined for a single interface.

Multicast One to Many An address for a set of interfaces Delivered to a group of interfaces identified by that address. Replaces IPv4 “broadcast”

Anycast One to Nearest (Allocated from Unicast) Delivered to the closest interface as determined by the IGP

A single interface may be assigned multiple IPv6 addresses of any type (unicast, anycast, multicast) An example of IPv6: 2001:0000:5723:0000:0000:D14E:DBCA:0764

There are: 8 groups of 4 hexadecimal digits. Each group represents 16 bits (4 hexa digits * 4 bit) Separator is “:” Hex digits are not case sensitive, so “DBCA” is same as “dbca” or “DBca”… IPv6 (128-bit) address contains two parts: The first 64-bits is known as the prefix. The prefix includes the network and subnet address. Because addresses are allocated based on physical location, the prefix also includes global routing information. The 64-bit prefix is often referred to as the global routing prefix. The last 64-bits is the interface ID. This is the unique address assigned to an interface.

16

Note: Addresses are assigned to interfaces (network connections), not to the host. Each interface can have more than one IPv6 address.

Rules for abbreviating IPv6 Addresses: Leading zeros in a field are optional 2001:0DA8:E800:0000:0260:3EFF:FE47:0001 can be written as 2001:DA8:E800:0:260:3EFF:FE47:1 Successive fields of 0 are represented as ::, but only once in an address: 2001:0DA8:E800:0000:0000:0000:0000:0001 -> 2001:DA8:E800::1 Other examples: FF02:0:0:0:0:0:0:1 => FF02::1 3FFE:0501:0008:0000:0260:97FF:FE40:EFAB = 3FFE:501:8:0:260:97FF:FE40:EFAB = 3FFE:501:8::260:97FF:FE40:EFAB 0:0:0:0:0:0:0:1 => ::1 0:0:0:0:0:0:0:0 => :: IPv6 Addressing In Use: IPv6 uses the “/” notation to denote how many bits in the IPv6 address represent the subnet. The full syntax of IPv6 is

ipv6-address/prefix-length

The ipv6-address is the 128-bit IPv6 address /prefix-length is a decimal value representing how many of the left most contiguous bits of the address comprise the prefix. Let’s analyze an example: 2001:C:7:ABCD::1/64 is really 2001:000C:0007:ABCD:0000:0000:0000:0001/64 The first 64-bits 2001:000C:0007:ABCD is the address prefix The last 64-bits 0000:0000:0000:0001 is the interface ID /64 is the prefix length (/64 is well-known and also the prefix length in most cases)

The Internet Corporation for Assigned Names and Numbers (ICANN) is responsible for the assignment

of IPv6 addresses. ICANN assigns a range of IP addresses to Regional Internet Registry (RIR) organizations.

The size of address range assigned to the RIR may vary but with a minimum prefix of /12 and belong to the

following range: 2000::/12 to 200F:FFFF:FFFF:FFFF::/64.

Each ISP receives a /32 and provides a /48 for each site-> every ISP can provide 2(48-32) = 65,536 site

addresses (note: each network organized by a single entity is often called a site).

Each site provides /64 for each LAN -> each site can provide 2(64-48) = 65,536 LAN addresses for use in their

private networks.

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So each LAN can provide 264 interface addresses for hosts.

Global routing information is identified within the first 64-bit prefix.

Note: The number that represents a range of addresses is called a prefix.

An example of IPv6 prefix: 2001:0A3C:5437:ABCD::/64:

In this example, the RIR has been assigned a 12-bit prefix. The ISP has been assigned a 32-bit prefix and

the site is assigned a 48-bit site ID. The next 16-bit is the subnet field and it can allow 216, or 65536 subnets.

This number is redundant for largest corporations on the world!

The 64-bit left (which is not shown the above example) is the Interface ID or host part and it is much bigger:

64 bits or 264 hosts per subnet!

For example, from the prefix 2001:0A3C:5437:ABCD::/64 an administrator can assign an IPv6 address

2001:0A3C:5437:ABCD:218:34EF:AD34:98D to a host.

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IPv6 Address Scopes

Address types have well-defined destination scopes:

IPv6 Address Scopes

Description

Link-local address Only used for communications within the local subnetwork (automatic address configuration, neighbor discovery, router discovery, and by many routing protocols). It is only valid on the current subnet.

Routers do not forward packets with link-local addresses. Allocated with the FE80::/64 prefix -> can be easily recognized by the prefix FE80. Some books indicate the range of link-local address is FE80::/10, meaning the first 10 bits are fixed and link-local address can begin with FE80, FE90,FEA0 and FEB0 but in fact the next 54 bits are all 0s so you will only see the prefix FE80 for link-local address.

Same as 169.254.x.x in IPv4, it is assigned when a DHCP server is unavailable

and no static addresses have been assigned Is usually created dynamically using a link-local prefix of FE80::/10 and a 64-bit interface identifier (based on 48-bit MAC address).

Global unicast address

Unicast packets sent through the public Internet

Globally unique throughout the Internet Starts with a 2000::/3 prefix (this means any address beginning with 2 or 3). But in the future global unicast address might not have this limitation

Site-local address Allows devices in the same organization, or site, to exchange data.

Starts with the prefix FEC0::/10. They are analogous to IPv4′s private address classes. Maybe you will be surprised because Site-local addresses are no longer supported (deprecated) by RFC 3879 so maybe you will not see it in the future.

All nodes must have at least one link-local address, although each interface can have multiple addresses. However, using them would also mean that NAT would be required and addresses would again not be end-to-end. Site-local addresses are no longer supported (deprecated) by RFC 3879.

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Special IPv6 Addresses

Reserved Multicast Address

Description

FF02::1 All nodes on a link (link-local scope).

FF02::2 All routers on a link

FF02::5 OSPFv3 All SPF routers

FF02::6 OSPFv3 All DR routers

FF02::9 All routing information protocol (RIP) routers on a link

FF02::A EIGRP routers

FF02::1:FFxx:xxxx All solicited-node multicast addresses used for host auto-configuration and neighbor discovery (similar to ARP in IPv4) The xx:xxxx is the far right 24 bits of the corresponding unicast or anycast address of the node

FF05::101 All Network Time Protocol (NTP) servers

Reserved IPv6 Multicast Addresses

Reserved Multicast Address

Description

FF02::1 All nodes on a link (link-local scope).

FF02::2 All routers on a link

FF02::9 All routing information protocol (RIP) routers on a link

FF02::1:FFxx:xxxx All solicited-node multicast addresses used for host auto-configuration and neighbor discovery (similar to ARP in IPv4) The xx:xxxx is the far right 24 bits of the corresponding unicast or anycast address of the node

FF05::101 All Network Time Protocol (NTP) servers

Use this link to view an excellent IPv6 demonstration using - Cisco Packet Tracer: https://www.youtube.com/watch?v=nO_ljrejtfE#t=12 “How to Route IPv6 Basics with Packet Tracer” iPv6 Part 1 through 3 especially for CCNAs https://www.youtube.com/watch?v=mvlBMogudkQ Part 1 of 3 https://www.youtube.com/watch?v=RkhK-JliNUY Part 2 of 3 https://www.youtube.com/watch?v=KarfIfI3frM Part 3 of 3