IP Protocol

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IP Protocol
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IP Protocol

• The Internet Protocol (IP) is a network-layer
  (Layer 3) protocol that contains addressing
  information and some control information that
  enables packets to be routed.
• IP is documented in RFC 791 and is the primary
  network-layer protocol in the Internet protocol
  suite. Along with the Transmission Control
  Protocol (TCP), IP represents the heart of the
  Internet protocols.
• IP has two primary responsibilities
• providing connectionless, best-effort delivery
  of datagrams through an internetwork.
• providing fragmentation and reassembly of
  datagrams to support data links with different
  maximum-transmission unit (MTU) sizes.

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IP Protocol

• IP Doesnt support reliability there aro no acks,
  error correction ,retransmissions or flow control
  , only checksum.

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IP Protocol
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IP Protocol
VersionIndicates the version of IP currently
used.
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IP Protocol
IP Header Length (IHL)Indicates the datagram
header length in 32-bit words.
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IP Protocol
Type-of-ServiceSpecifies how an upper-layer
protocol would like a current datagram to be
handled, and assigns datagrams various levels of
importance.
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IP Protocol
8 bits Bits 0-2 Precedence. 111 - Network
Control 110 - Internetwork Control 101 -
CRITIC/ECP 100 - Flash Override 011 Flash
010 Immediate 001 Priority 000 - Routine
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IP Protocol
8 bits Bit 3 0 Normal Delay 1 Low Delay.
Bits 4 0 Normal Throughput, 1 High
Throughput. Bits 5 0 Normal Relibility, 1
High Relibility. Bit 6-7 Reserved for Future
Use.
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IP Protocol
Total LengthSpecifies the length, in bytes, of
the entire IP packet, including the data and
header.
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IP Protocol
IdentificationContains an integer that
identifies the current datagram. This field is
used to help piece together datagram fragments.
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IP Protocol
FlagsConsists of a 3-bit field of which the two
low-order (least-significant) bits control
fragmentation. The low-order bit specifies
whether the packet can be fragmented. The middle
bit specifies whether the packet is the last
fragment in a series of fragmented packets. The
third or high-order bit is not used.
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IP Protocol
Bit 0 reserved, must be zero Bit 1 (DF) 0
May Fragment 1 Don't Fragment. Bit 2 (MF) 0
Last Fragment, 1 More Fragments.
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IP Protocol
Fragment OffsetIndicates the position of the
fragment's data relative to the beginning of the
data in the original datagram, which allows the
destination IP process to properly reconstruct
the original datagram.
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IP Protocol
Time-to-LiveMaintains a counter that gradually
decrements down to zero, at which point the
datagram is discarded. This keeps packets from
looping endlessly.
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IP Protocol
ProtocolIndicates which upper-layer protocol
receives incoming packets after IP processing is
complete.
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IP Protocol
Header ChecksumHelps ensure IP header integrity.
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IP Protocol
Source AddressSpecifies the sending node.
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IP Protocol
Destination AddressSpecifies the receiving node.
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IP Protocol
OptionsAllows IP to support various options,
such as security.
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IP Protocol
DataContains upper-layer information.