WHAT - IP Address
Unique 32 or 128 bit Binary, used to
identify a system on a Network or Internet.
Network Portion Host
CLASSFULL ADDRESSING
Network and Host IDs
• Each IP address is divided into two parts
– Network part, defined by netid – identifies a network
Class A Address
• Network Bits = 7
No.of Networks = 27 – 1 = 127
• Host Bits = 24
No.of Host/NW = 224 – 2 = 16 Million
• Range :
0.0.0.0 to 127.255.255.255
Class B Address • Network Bits = 14 No.of Networks = 214 – 1 = 16,383 • Host Bits = 16 No.of Host/NW = 216 – 2 = 65,234 • Range : 128.0.0.0 to 191.255.255.255
Class C Address
• Network Bits = 21
No.of Networks = 221 – 1 = 2 Million
• Host Bits = 8
No.of Host/NW = 28 – 2 = 254
• Range :
192.0.0.0 to 223.255.255.255
Special Purpose IP Addresses
• Private IP Address
Private IP Addresses
• Private addresses are not recognized globally
Other Special Addresses
Direct Broadcast
Limited Broadcast
This Host on This network
• The network address that consists of all 0s indicates this host on this network.
– Used at the bootstrap time when host does not know its IP address.
– This address is used as a source address in limited broadcast message to determine its IP address.
Specific Host on This
network
• The network address that consists of all 0s for netid and specific value for hostid is destined to a specific host on THIS network
– Used a host to send a message to another host on same network. – This address can only be used as destination
Loopback Address
• IP address with first byte value of 127 is used for the loopback address.
– Packets with such destination address never leave the machine
• Loopback can be used only as destination address
• Loopback is class A address which reduces the number of class A addresses by 1 block
Loopback address can be used for
Testing IP software,
SUBNETTING &
SUBNETTING
WHAT
• Subnetting is dividing a network into several smaller parts (subnets), each having its own sub-network address.
• Traditional Internet uses two-level address hierarchy: netids and hostids
• Subnetting provides another, third, level of hierarchy.
Network Portion Subnet
Portion
SUBNETTING
WHY
More EFFICIENT & STRUCTURED utilization of IP Address
SUBNET MASK OR NETMASK WHAT
A Bit stream of Contiguous ONES & ZEROS
WHY
SUBNET MASK OR NETMASK TYPES
• Natural / Default Network Mask
Creating Subnets Using Masks
• WE EXTEND THE NETWORK PORTION INTO HOST • Mask is a 32‐bit number that consists of – Consecutive 1s indicating bits that belong to the network part of address followed by – Consecutive 0s indicating bits that do not belong to network part of the address Bit-wise AND operation
Subnet Masks
• Subnet masks operate the same way as default masks.
SUPERNETTING
Supernetting
• In supernetting, the first address of the supernet and the supernet mask define the range of addresses.
CIDR notation is applicable to suppernetting as well.
For example:
201.12.192.3/21
Shows that address belongs to supernet of class C networks with mask
255.255.248.0
VLSM
VLSM
Eg : a Class C, NW need to be divided into 110,45,50 Hosts?
Available Options 2 :‐
The Subnet Mask of the form 255.255.255.X
X (in Binary) X No of Subnets No of Hosts
VLSM -option
ICMP
ICMP Encapsulation
ICMP
ICMP
MESSAGE FORMAT
General format of ICMP messages
Category Type Message
ICMP
MESSAGE FORMAT ERROR REPORTING MSG
Time Exceeded
• Whenever a router decrements a datagram
with a time‐to‐live value to zero, it discards the datagram and sends a time‐exceeded message to the original source.
• When the final destination does not receive all
Parameter‐problem message
• Code 0 : Error on Header (Value of pointer points to the byte with problem)
Echo Request Reply
• An echo‐request message can be sent by a host or router.
An echo‐reply message is sent by the host or router which receives an echo‐request message.
• Echo‐request and echo‐reply messages can be used by
network managers to check the operation of the IP protocol.
• Echo‐request and echo‐reply messages can test the
Checksum
DEBUGGING TOOLS
Ping
PING
The ping program to test the server fhda.edu. The result is shown below
$ ping fhda.edu
PING fhda.edu (153.18.8.1) 56 (84) bytes of data.
PING
64 bytes from tiptoe.fhda.edu (153.18.8.1): icmp_seq=5 ttl=62 time=2.00 ms 64 bytes from tiptoe.fhda.edu (153.18.8.1): icmp_seq=6 ttl=62 time=1.94 ms 64 bytes from tiptoe.fhda.edu (153.18.8.1): icmp_seq=7 ttl=62 time=1.94 ms 64 bytes from tiptoe.fhda.edu (153.18.8.1): icmp_seq=8 ttl=62 time=1.97 ms 64 bytes from tiptoe.fhda.edu (153.18.8.1): icmp_seq=9 ttl=62 time=1.89 ms 64 bytes from tiptoe.fhda.edu (153.18.8.1): icmp_seq=10 ttl=62 time=1.98 ms
fhda.edu ping statistics
Traceroute
We use the traceroute program to find the route from the computer voyager.deanza.edu to the server fhda.edu :
$ traceroute fhda.edu
Serial Line IP Protocol
SLIP - SLIP is a standard protocol for
point-to-point serial connections, using TCP/IP. SLIP was a predecessor of PPP.
PROBLEM WITH SLIP PROTOCOL
• No Error detection.
• It supports only IP.
• It is not possible to dynamically assign the address during the set up.
• Slip does not provide any Authentication.
POINT TO POINT PROTOCOL
PPP provides router‐to‐router and host‐to‐network connections over synchronous and asynchronous circuits.
9 SERVICES PROVIDED BY PPP:‐
• The PPP protocol can operate over a full duplex point to point transmission link as well as over asynchronous links.