TCP/IP

Transmission Control Protocol / Internet Protocol

OSI 7 LAYERS= " All People Seem To Need Data Professionals!"

The TCP/IP layers Versus OSI model

Application Layer is formed by the Session,Presentation, and Application Layers of the OSI model

In the Application layer we find the followings main protocols

File Transfer:

FTP (File Transfer Protocol)

SMTP (Simple Management

TFTP ( Trivial File Transfer Protocol)

Telnet

Remote Login: Telnet, Rlogin (Remote Login)

Network Management: SNMP (Simple Network Management Protocol)

E-mail : SMTP (Simple Mail Transfer Protocol)

The Transport layer coincide with the Transport layer of the OSI Model

TCP (Transmission Control Protocol define by RFC 793)

The following services use TCP protocol:

DNS, SMTP,FTP,Telnet, NTP, HTTP, X-windows,

UDP (Unreliable Datagram Protocol )

The following Services use UDP protocol:

DNS, SNMP,DHCP, BooTP,NTP, TFTP,

The Internet layer is the Network layer of the OSI model

We find in the network layer several protocols:

IP (Internet Protocol). Network and Node address are set defined by RFC791

ICMP (Internet Control Message Protocol). Sub-protocol of IP defined by

RFC 792 . Ensured that the ICMP message will find appropriate

host within a group of subnets. Example of service: Ping command.

ARP (Address Resolution Protocol). Map IP address to MAC addresses

RARP (Reverse Address Resolution Protocol). Resolve Hardware-MAC

address that do not know yet their IP address (example Diskless PC)

InARP Inverse Address Resolution Protocol. Used in None broadcast networks such frame relays. Dynamically associate a remote data link connection identifier with an IP address

The Network Interface layer is formed by the DataLink and Physical Layer of the OSI model

IP Address Space

An IP Address is 32 bits in length. A unique IP Address is required for all hosts using TCP/IP.

IP Address

32 BITS

8 bits or 1 byte

1 or 0

First Octet

Second Octet

Third Octet

Fourth Octet

0-255 dotted decimal notation

(255-0)+1 = 256 different possible decimal numbers

Structure of the IP address

4 octets	1^st Octet	2^nd Octet	3^rd Octet	4^th Octet
32 bits	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx

Classes of IP .(The usable range restrictions)

Certain addresses in the IP address space have been reserved for special purposes, and are not allowed as host addresses. The rules for these IP address are

The Network address portion of an IP address can not be set to "all binary zeroes" or "all binary ones"

The subnet portion of an IP address can not be set to "all binary ones" or "all binary zeroes"

The host address portion of an IP address can not be set to "all binary ones" or "all binary zeros"
The Network 127.xxx can not be used as a network address (loop back)

Broadcast

Local Broadcast: When all bits are set to ones.
Subnet broadcast: All the subnet address bits are set to ones

Address Class	Bit Pattern in the 1^st Octet	Range of Address
	7 6 5 4 3 2 1 0 bits
Class A	0 x x x x x x x	1 - 126
Class B	1 0 x x x x x x	128 - 191
Class C	1 1 0 x x x x x	192 - 223
Class D	1 1 1 0 x x x x	224 - 239
Class E	1 1 1 1 x x x x	240 - 255

CLASS	Subnet Mask	Network bits	Network	Host Bits	Host
Class A	255.0.0.0	8	126	24	15,777,206
Class B	255.255.0.0	16	16,383	16	65,533
Class C	255.255.255.0	24	2,097,151	8	254

HEX and Binary Values

	Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
Base 2 (Binary)	128	64	32	16	8	4	2	1
Base 16 (Hex)	268,435,456	16,777,216	1,048,576	65,536	4, 096	256	16	1

Bits Used Versus Number of (Host - 2)use for broadcast)

Sub-net Bits	Class A host	Class B Host	Class C host
0	16,777,214	65,534	254
1	8,388,606	32,766	126
2	4,194,302	16,382	62
3	2,097,150	8,190	30
4	1,048,574	4,094	14
5	524,286	2,094	6
6	262,142	1,022	2
7	131,070	510	--
8	65,533	254	--

Subnet Bits used and Sub-Net-Networks

Sub-net Bits	First Sub-net	Interval Between Sub-net	Number of Sub-nets
2	64	64	2
3	32	32	6
4	16	16	14
5	8	8	30
6	4	4	62
7	2	2	126
8	1	1	254

BITS Used in the IP Mask versus the Sub-Net Networks

Bits Added To Mask	Decimal Value	Number of Subnet
1	128	0
2	192	2
3	224	6
4	240	14
5	248	30
6	252	62
7	254	126
8	255	254
9	255.128	510
10	255.192	1022
11	255.224	2046
12	255.240	4094
13	255.248	8190
14	255.252	16,382
15	255.254	32,766
16	255.255	65,534

Example for an Address Class B

IP address: 135.120.0

IP Mask: 255 . 255 . 224 . 0

SubNet Bit Pattern 3^rd Octect	Subnet Value		Subnet Address
000xxxxx	0		135.120.0.0	Not Usable
001xxxxx	32		135.120.32.0	Ok
010xxxxx	64		135.120.64.0	Ok
011xxxxx	96		135.120.96.0	Ok
100xxxxx	128		135.120.128.0	Ok
101xxxxx	160		135.120.160.0	Ok
110xxxxx	192		135.120.192.0	Ok
111xxxxx	224		135.120.224.0	Not Usable
Function		Example			Comments
*First Sub-net Address*		135.120.32.0
First Host		135.120.32.1
Last Host		135.120.32.254
Sub-Net BroadCast		135.120.32.255
*Next SubNet Address*		135.120.64.0

SUB-NETWORKS PATTERN FOR CLASS C

Bits	1^st Octet Network	2^nd Octet Network	3^rd Octet Network	4^thOctect Host	Total Available
Borrow	76543210	76543210	76543210	7 6 5 4 3 2 1 0	Network	Host
0	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	0 0 0 0 0 0 0 0	1	256
1	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 0 0 0 0 0 0 0	2	128
2	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 1 0 0 0 0 0 0	4	64
3	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 1 1 0 0 0 0 0	8	32
4	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 1 1 1 0 0 0 0	16	16
5	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 1 1 1 1 0 0 0	32	8
6	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 1 1 1 1 1 0 0	64	4
7	Xxxxxxxx	Xxxxxxxx	Xxxxxxxx	1 1 1 1 1 1 1 0	128	2

Class C IP Address RANGE

Network Class	First Octet	Fixed High Order Bits	*# of Networks*	*# of Hosts per network*
Class C	192 - 223	110	(2^21) = 2, 097,152	(2^8) - 2 = 254

Class C Network ID: (192 -223) . (0 - 255) . (0-255) . x
Class C Host ID: (x . x . x ) . (1-254)
Default Subnet Mask: 255 . 255 . 255 . 0

Subnetting a Class C IP Address

Class C IP Address Subnet Mask: 255 . 255 . 255 .192 (2 bits)

2 Subnets and 62 Hosts per Subnet

Subnet	*Host Range*
1	(x . x . x .65 ) - (x . x . x .126 )
2	(x . x . x .129 ) - (x . x . x .190 )

Class C IP Address Subnet Mask: 255 . 255 .255 .224 (3 bits)

6 Subnets and 30 Hosts per Subnet

Subnet	*Host Range*
1	( x . x . x . 33 ) - ( x . x . x . 62 )
2	( x . x . x . 65 ) - ( x . x . x . 94 )
3	( x . x . x . 97 ) - ( x . x . x . 126 )
4	( x . x . x . 129) - ( x . x . x . 158 )
5	( x . x . x . 161) - ( x . x . x . 190 )
6	( x . x . x . 193) - ( x . x . x . 222 )

Class C IP Address Subnet Mask: 255.255.255.240 (4 bits)

14 Subnets and 14 Hosts per Subnet

Subnet	*Host Range*
1	(x . x . x .17 ) - (x . x . x .30 )
2	(x . x . x .33 ) - (x . x . x .46 )
3	(x . x . x .49 ) - (x . x . x .62 )
4	(x . x . x .65 ) - (x . x . x .78 )
5	(x . x . x .81 ) - (x . x . x .94 )
6	(x . x . x .97 ) - (x . x . x .110 )
7	(x . x . x .113 ) - (x . x . x .126 )
8	(x . x . x .129 ) - (x . x . x .142 )
9	(x . x . x .145 ) - (x . x . x .158 )
10	(x . x . x .161 ) - (x . x . x .174 )
11	(x . x . x .177 ) - (x . x . x .190 )
12	(x . x . x .193 ) - (x . x . x .206 )
13	(x . x . x .209 ) - (x . x . x .222 )
14	(x . x . x .225 ) - (x . x . x .238 )

Other Sub-Nets for 5 and 6 bits results in

Class C IP Address Subnet Mask:

255.255.255.248 (5 bits)

30 Subnets 6 Hosts per Subnet

Class C IP Address Subnet Mask: (6 bits)

62 Subnets 2 Hosts per Subnet

Decimal to Hexadecimal Quick Conversion

Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex
0	0	32	20	64	40	96	60	128	80	160	a0	192	c0	224	e0
1	1	33	21	65	41	97	61	129	81	161	a1	193	c1	225	e1
2	2	34	22	66	42	98	62	130	82	162	a2	194	c2	226	e2
3	3	35	23	67	43	99	63	131	83	163	a3	195	c3	227	e3
4	4	36	24	68	44	100	64	132	84	164	a4	196	c4	228	e4
5	5	37	25	69	45	101	65	133	85	165	a5	197	c5	229	e5
6	6	38	26	70	46	102	66	134	86	166	a6	198	c6	230	e6
7	7	39	27	71	47	103	67	135	87	167	a7	199	c7	231	e7
8	8	40	28	72	48	104	68	136	88	168	a8	200	c8	232	e8
9	9	41	29	73	49	105	69	137	89	169	a9	201	c9	233	e9
10	a	42	2a	74	4a	106	6a	138	8a	170	aa	202	Ca	234	ea
11	b	43	2b	75	4b	107	6b	139	8b	171	ab	203	Cb	235	eb
12	c	44	2c	76	4c	108	6c	140	8c	172	ac	204	Cc	236	ec
13	d	45	2d	77	4d	109	6d	141	8d	173	ad	205	Cd	237	ed
14	e	46	2e	78	4e	110	6e	142	8e	174	ae	206	Ce	238	ee
15	f	47	2f	79	4f	111	6f	143	8f	175	af	207	Cf	239	ef
16	10	48	30	80	50	112	70	144	90	176	b0	208	d0	240	f0
17	11	49	31	81	51	113	71	145	91	177	b1	209	d1	241	f1
18	12	50	32	82	52	114	72	146	92	178	b2	210	d2	242	f2
19	13	51	33	83	53	115	73	147	93	179	b3	211	d3	243	f3
20	14	52	34	84	54	116	74	148	94	180	b4	212	d4	244	f4
21	15	53	35	85	55	117	75	149	95	181	b5	213	d5	245	f5
22	16	54	36	86	56	118	76	150	96	182	b6	214	d6	246	f6
23	17	55	37	87	57	119	77	151	97	183	b7	215	d7	247	f7
24	18	56	38	88	58	120	78	152	98	184	b8	216	d8	248	f8
25	19	57	39	89	59	121	79	153	99	185	b9	216	d9	249	f9
26	1a	58	3a	90	5a	122	7a	154	9a	186	ba	218	da	250	fa
27	1b	59	3b	91	5b	123	7b	155	9b	187	bb	219	db	251	fb
28	1c	60	3c	92	5c	124	7c	156	9c	188	bc	220	dc	252	fc
29	1d	61	3d	93	5d	125	7d	157	9d	189	bd	221	dd	253	fd
30	1e	62	3e	94	5e	126	7e	158	9e	190	be	222	de	254	fe
31	1f	63	3f	95	5f	127	7f	159	9f	191	bf	223	df	255	ff