IP Networking Part 3IP Address Management
“A webinar to help you prepare
for the CBNE™ Certification”
Wayne M. Pecena, CPBE, CBNE
Texas A&M Information Technology
Educational Broadcast Services
IP Networking, Part 3 - IP Address Management
“A webinar to help you prepare for the CBNE™ Certification”
Advertised Presentation Scope:
IP Networking Fundamentals for Broadcast Engineers is an intensive instructorlead workshop focused on major IP networking topics. The goal is to equip the
broadcast engineer with the knowledge and understanding of IP networking
fundamentals and the ability to apply conceptual theory in a practical manner.
The workshop will focus upon the principals of IP Addressing and application
of best practices in the design of an IP network address plan.
My Goals & Deliverables for This Afternoon:
-
Provide an Awareness of Major IP Networking Topics (broadcast application focused)
Provide an Understanding of IP Addressing Fundamentals
Provide a Foundation for SBE CBNT & CBNE Certification Exams
Provide Reference Material & Resources to Obtain Further Knowledge
2
A Poll ?
• My Familiarity & Conformability with IP
Addressing is:
Not at All
Somewhat
Familiar, But I Struggle At Times
Very Comfortable, I Am Here for the Free Lunch
3
IP Networking, Part 3 - IP Address Management
“A webinar to help you prepare for the CBNE™ Certification”
•
•
•
•
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IP Address Basics (IPv4)
IP Addressing Rules
IP Address Classes
IP Subnetting Fundamentals
The IPv6 Address
Practical Exercises:
– Reverse Engineering an IP Address Plan
– Developing an IP Addressing Plan
4
REVIEW - Physical & Virtual Addressing
• Each Host on an Ethernet Based IP Network Has:
• An Unique MAC Address
– Layer 2 Physical Address (local network segment)
• An Unique IP Address
– Layer 3 Logical Address (global routed)
Simplified Representation
FF:FF:FF:FF:FF:FF
Destination
MAC
00:12:3F:8D:4D:A7
Source
MAC
172.15.1.1
172.15.2.2
Source
IP
Destination
IP
DATA
Trailer
IP Packet
Ethernet Frame
5
The IP Address:
• Is a “Logical Address” – OSI Model Layer 3 Function
– Allows Hierarchical Network Addressing Structure
• Creates Boundaries Between Networks
– Allows Routing Packets Between Networks
• Must Have a Subnet Mask:
– Implied
– Explicit
• Address & Mask Defines:
– Unique Network ID
– Unique Host ID
6
The IP Address (IPv4)
32 Bit Address Yields 4,294,967,296 IPv4 Addresses
Expressed in Decimal as (4) 8-bit Octets using “Doted Decimal Notation”
192.168.10.1
11000000.10101000.00001010.00000001
128
64
32
16
8
4
2
1
1
1
0
0
0
0
0
0
128
64
32
16
8
4
2
1
0
0
0
0
0
0
0
1
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The IP Address Subnet Mask
Each IP Address Must Have a Subnet Mask
32 Bit Subnet Mask
Expressed in Decimal as (4) 8-bit Octets using “Doted Decimal Notation”
255.255.255.192
11111111.11111111.11111111.11000000
128
64
32
16
8
4
2
1
1
1
1
1
1
1
1
1
128
64
32
16
8
4
2
1
1
1
0
0
0
0
0
0
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Purpose of the Subnet Mask
• Identifies the Network Portion and the Host Portion
of the IP Address
– Classful Addressing – Mask is Implied Based Upon Class
– Classless Addressing – Mask Must Be Specified
Octet 1
Class A
Class B
Octet 2
Octet 4
NET ID
HOST ID
8 Bits
24 Bits
NET ID
HOST ID
16 Bits
16 Bits
Class C
Octet 3
NET ID
HOST ID
24 Bits
8 Bits
9
The Subnet Mask:
• Rules:
– If Mask Bit =1
– If Mask Bit=0
Identifies the Network
Identifies the Host
192.168.10.1 255.255.255.192
11000000.10101000.00001010.00000001
Address
11111111.11111111.11111111.11000000
Mask
Network
Host
Class
Octet 1
Octet 2
Octet 3
Octet 4
A
Network
Host
Host
Host
B
Network
Network
Host
Host
C
Network
Network
Network
Host
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IP Address Classes
Used to Set Different Network Sizes
• The 1st Octet of an IP Address Determines It’s
Class:
Class
A
First Octet
Subnet Mask
(implied)
CIDR
Maximum #
of Networks
#
Host
Bits
# of Hosts /
Network
1 - 127
255.0.0.0
/8
127
24
16,777,214
/16
16,384
16
65,534
2,097,152
8
254
B
128 - 191 255.255.0.0
C
192 - 223 255.255.255.0 /24
The 1st Octet of an IP Address Dictates the Class
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The 1st Octet of an IP Address Determines It’s Class:
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•
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•
•
If First Bit = 0
If First 2 Bits = 10
If First 3 Bits – 110
If First 4 Bits = 1110
If First 4 Bits = 1111
Class A
Class B
Class C
Class D
Class E
• Recognize Class D & E Are “Special”:
– Class D
– Class E
Reserved for Multicast
Reserved for Experimental
12
A Quiz!
• What Class Are the Following IP Addresses?
169.254.0.100
127.10.0.10
Class A
Class B
Class C
Class D
Class A
Class B
Class C
Class D
223.127.169.254
Class A
Class B
Class C
Class E
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The Network & Broadcast Addresses
• These Addresses Cannot Be Assigned to a Host!
– Network (subnet) Address
• ALL HOST BITS = 0
– Broadcast Address
• ALL HOST BITS = 1
• Network Example:
• Broadcast Example:
00000000
192.168.1.0 /24
192.168.1.255 /24
11111111
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Private vs Public IP Addresses
• RFC 1918 Established “Private” Address Space
– Class A: 10.0.0.0 to 10.255.255.255
– Class B: 172.16.0.0 to 172.31.255.255
– Class C: 192.168.0.0 to 192.168.255.255
/8
/16
/24
• Key Points:
– Private IP Addresses Are NOT Routable Outside the Local Network or
to the Internet
– Widely Used in Home & Industry Networks
– May Be Translated With NAT At An Edge Router
• Map Private Address Space to Public Address Space
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CIDR
RFC 1517, 1518, 1519, 1520
• Classless Inter-Domain Routing (CIDR)
– Simplified Approach to Stating the Subnet Mask
– / Notation (slanted notation) Utilized = # Bits That Are 1
Mask:
255.255.255.240
Expressed in Binary:
11111111.11111111.11111111.11110000
24 Bits
Mask (CIDR):
/28
16
IP Address & Subnet Mask Formats
Classful Addressing:
165.95.240.136
(Implied Mask 255.255.0.0)
VLSM Addressing:
165.95.240.136 255.255.255.192
CIDR Notation :
165.95.240.136 /26
Implied Mask
Of a Class B Network
Explicit Mask
Must Be Stated
Mask Stated as
Number of Subnet Bits
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Special Use IP Addresses
RFC 5735
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•
•
0.0.0.0/8
Network Address “Wire Address”
10.0.0.0/8
Private IP Address Space (RFC 1918)
127.0.0.0/8
Loopback Address
169.254.0.0/16
IETF Zero Configuration Address Space (RFC 3927)
172.16.0.0/16
Private IP Address Space (RFC 1918)
192.168.0.0/16
Private IP Address Space (RFC 1918)
224.0.0.0/4
Multicast Address Space
255.255.255.255/32 Broadcast Address
And more special use cases………..yields a little over 3.7m “Useable IPv4 Addresses”
(3,706,650,624 out of 4,294,967,296 possible IPv4 addresses or 86%)
18
IP Address Trivia
• What is Special About 127.0.0.1 ?
– Actually Any 127.0.0.0/8 Address Works OR the Range of
127.0.0.1 to 127.255.255.255
• Known as a “Loop-Back” Address
• Useful For:
– Test Local IP Stack and Network Adapter Test
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IP Address Subnetting
•
What is a Subnet?
– Logical Subdivision of a Larger Network
– Creates New Networks From A Larger Network
– Bits Are “Stolen” From the Host Portion
• Each Newer Network Created Has Less Hosts
• 2n-2 New Networks Created
where n=number of host bits stolen
•
Why Do We Subnet?
Efficient Use of IP Address Space (“Right Size” the Network)
Increase Performance (smaller Broadcast domain)
Enhance Routing Efficiency (reduce Routing Table size)
Network Management Policy and Segmentation
(function, ownership, geo location)
– Job Security for Network Engineers!
–
–
–
–
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Subnetting Simply Moves the Boundary between the Network and Host
Moves Boundary to the Right
Boundary Position Determined by the Subnet “Netmask”
Provided IP Address Space: 200.25.0.0/16
Represents 4,096 IP Addresses
Or 256 /24 Class “C” Blocks
200.25.31.0/24
200.25.30.0/24
Provided IP Address Space: 200.25.0.0/16
Represents 4,096 IP Addresses
200.25.16.0/24
16
200.25.17.0/24
1
200.25.30.0/23
2
15
D
200.25.18.0/24
200.25.29.0/24
3
14
200.25.28.0/23
13
4
12
5
C
A
200.25.16.0/21
6
11
B
7
10
9
8
200.25.24.0/22
200.25.24.0/24
200.25.23.0/24
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Subnetting Basics
• Identifies the Boundary Between Network and Hosts
• “Subnetting” Simply Moves the Boundary!
– Moves Boundary to the Right
– IP Address Subnetting Applies to All Classes
– Boundary Position Determined by the Subnet “Netmask”
• Expressed in Several Forms:
– Doted Decimal Notation (same as IP address)
– Slash Notation (also known as CIDR notation)
IP Address 165.95.240.100 with Netmask of 255.255.255.0
OR
165.95.240.100 /24
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Required Host IP Configuration
Information
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•
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IP Address
Address Mask
Gateway Address
DNS Server Address(s)
Where Do We Get This Information?
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Network Questions to Answer
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How Many Subnets Are Available?
How May Hosts per Subnet Are Available?
What Are the Subnets?
What is the Broadcast Address of Each Subnet?
What Are the Valid Hosts in Each Subnet?
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What Must Be Known About a Network?
IP Address and Mask
Provides:
First Network Address
First Network Address Assignable to a Host
Last Network Address Assignable to a Host
Broadcast Address
192.168.1.0 /24
Provides: 254 useable IP addresses
Mask: 255.255.255.0
Network Address (Wire Address)
First Network Address Assignable to a Host
Last Network Address Assignable to a Host
Broadcast Address
192.168.1.0
192.168.1.1
192.168.1.254
192.168.1.255
26
Subnet Calculation Examples
192.168.1.0 /20
Provides: 4094 useable IP addresses
Mask: 255.255.240.0
Network Address (Wire Address)
192.168.0.0
First Network Address Assignable to a Host 192.168.0.1
Last Network Address Assignable to a Host 192.168.15.254
Broadcast Address
192.168.15.255
192.168.1.0 /28
Provides: 14 useable IP addresses
Mask: 255.255.255.240
Network Address (Wire Address)
First Network Address Assignable to a Host
Last Network Address Assignable to a Host
Broadcast Address
192.168.1.0
192.168.1.1
192.168.1.14
192.168.1.15
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An Exercise?
• Is 204.56.198.31 mask 255.255.255.224 a Valid Host IP
Address?
Yes
No
It Depends
28
Lets See!
204.56.198.31 mask 255.255.255.224
1.
Convert Mask to Binary – 255.255.255.224: 11111111.11111111.11111111.11100000
2.
Convert Mask to Inverse Mask:
subtract from all 1's
11111111.11111111.11111111.11111111
11111111.11111111.11111111.11100000
00000000.00000000.00000000.00011111
3.
AND IP Address & Mask: 204.56.198.31
255.255.255.224
00100100.00111000.11000110.00001111
11111111.11111111.11111111.11100000
00100100.00111000.11000110.00000000
Yields the Network Address:
204.56.198.0
4.
OR Inverse Mask to Network Address:
00100100.00111000.11000110.00000000
00000000.00000000.00000000.00011111
00100100.00111000.11000110.00011111
Yields the Broadcast Address:
204.56.198.31
5. Thus:
Network:
1st Host:
Last Host:
Broadcast:
204.56.198.0
204.56.198.1
204.56.198.30
204.56.198.31
The Answer Is NO
204.56.198.31 is Not a Valid
Host Address
(It’s the Broadcast Address)
29
IPv6 Address Space
IETF - RFC 2460
IPv6 Provides Expanded IP Address Space
2128 =
340,282,366,920,938,463,463,374,607,431,768,211,456
(three hundred forty UNDECILLION addresses)
3.4 x 1038
• But, IPv6 is More Than Expanded Address Space:
– An Opportunity to Re-Engineer IPv4
•
•
•
•
•
•
Improved Support for Multicasting, Security, & Mobile Aps
Multiple Addresses per Interface
Host Auto-Configuration Capability
Security Incorporated
MTU Discovery Incorporated
Traffic Engineering Provisions Incorporate
The IPv6 Address
128-Bit Address Binary Format:
001001100000011110111000000000001111101010100000000000110010000110010101100110001000011110111100010010000010100011110001
Subdivide Into Eight (8) 16-bit Groups:
0010011000000111 1011100000000000 0000111110101010 0000000000000011
0010000110010101 1001100010000111 1011110001001000 0010100011110001
Convert Each 16-bit Group to Hexadecimal:
(separate with a colon)
2607:b800:0faa:0003:2195:9887:bc48:28f1
2607:b800:faa:3:2195:9887:bc48:28f1
Address Summarization
128-Bit Address Represented as a 32 Hexadecimal Digits
Subdivided Into Eight Groups (Chunks, Quads, Quartets) of Four Hexadecimal Digits
(separated by colon)
2001:0000:0000:0000:0DB8:8000:200C:417A
or
2001:0:0:0:DB8:8000:200C:417A
or
2001::DB8:8000:200C:417A
Address Summarization
128-Bit Address Represented as a 32 Hexadecimal Digits
Subdivided Into Eight Groups (Chunks, Quads, Quartets) of Four Hexadecimal Digits
(separated by colon)
2001:0000:0000:0000:0DB8:8000:200C:417A
or
2001:0:0:0:DB8:8000:200C:417A
or
2001::DB8:8000:200C:417A
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33
An Ipv6 Address You Can Remember
The IPv6 Loopback Address
::1
Summarized from:
0:0:0:0:0:0:0:1
IP Addressing Reverse Engineering
“A Useful Troubleshooting Tool”
• Verifying Proper Subnet Configuration When Given an IP
Address and Subnet Mask
– Determine Subnet Address Range
– Determine “Assignable” IP Addresses
– Determine Broadcast Address
• Subnetting When Given A Network Requirement
• Subnetting When Given A Host Requirement
You Are Provided:
IP Address / IP Mask
35
IP Address Subnetting Charts
36
Subnet Calculation Tools
37
Hints for Subnetting
VLSM
Mask
128
192
224
240
248
252
254
255
128
64
32
16
8
4
2
1
/25
/26
/27
/28
/29
/30
/31
/32
CIDR
4th Octect
OR
AND
Remember
George Boole
Block
Size
0
0
0
0
0
0
0
1
0
0
1
1
1
0
0
1
0
1
1
1
1
1
1
1
38
Practical Exercise
Reverse Engineering an IP Address Plan
Refer to Exercise Handout
39
40
Practical Exercise #2
Developing an IP Addressing Plan
Refer to Exercise Handout
41
64
32
32
42
Subnet Number:
Subnet Mask:
192.168.100.0
255.255.255.192
First IP Address:
192.168.100.1
Broadcast IP Address:
192.168.100.63
Last IP Address:
192.168.100.62
Subnet Number:
192.168.100.64
Subnet Mask:
255.255.255.224
First IP Address:
192.168.100.65
Broadcast IP Address:
192.168.100.95
Last IP Address:
192.168.100.94
Subnet Number:
192.168.100.96
Subnet Mask:
255.255.255.224
First IP Address:
192.168.100.97
Broadcast IP Address:
192.168.100.127
Last IP Address:
192.168.100.126
What additional IP configuration
information is required to configure
hosts on this network?
Default Gateway
43
The Calculator Approach!
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Web Reference Sources:
•
Subnet Calculation Tools:
www.subnet-calculator.com
www.solarwinds.com/products/freetools/free_subnet_calculator.aspx
http://www.pkostov.com/wordpress/?p=66
iOS App $: https://itunes.apple.com/us/app/mask-ipv4-ipv6calculator/id329508400?mt=8
•
RFC Documents:
www.rfc-editor.org
•
IP Address Subnet Block Size Chart:
http://img.docstoccdn.com/thumb/orig/14990233.png
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Web Reference Sources continued…….
•
IP Subnetting – Cisco Networkers “Magic Box” Tutorial:
https://learningnetwork.cisco.com/docs/DOC-5893
– Cisco IP Subnetting Game:
https://learningnetwork.cisco.com/docs/DOC-1802
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CBNE Recommended Study:
48
My Favorites:
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? Questions ?
Thank You for Attending!
Wayne M. Pecena
Texas A&M University
w-pecena@tamu.edu
979.845.5662
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