2. Title and Content Layout with List
• TCP SLIDING WINDOW
• USER DATAGRAM PROTOCOL
• THE APPLICATION LAYER
• DNS
• NETWORK SECURITY EXPATIATION AND
THREATS IN TCP/IP
• FIREWALL
• Internet Protocol (IP)
• IP Packet Format
• IP addressing
• IP subnet
• Address Resolution Protocol
(ARP)
• Internet Routing
• ICMP
• TCP
3. Internet Protocol
• Internet protocol is a system protocol at (layer 3)
• Contain addressing data
• connectionless service
• No acknowledgement
• Datagrams transfer measured through (MTU)
5. IP addressing
Procedure of routing IP datagrams
IT has two primary parts
1 the network number (allocated by Nic)
2Host number (delegated by LNA)
ISP provides the network service
Address assign to Isp is by (IANA) Internet assigned number authority
7. IP subnet Addressing
• Two parts
• Subnet
• Host
• Public or Global IP
• Private or local
• IP subnet Mask ( binary number )
8. Broadcast Address
Directed broadcast address
• At the point when a packet is sent to a system's network broadcast address, a single duplicate of
it goes to network, and after that the packet is sent to each host on that system or subnet work
Limited Broadcast address
• On the off chance that the IP location is all ones (255.255.255.255), this is a restricted broadcast
address; the packet is meant to all hosts on the current (sub) network.
• A routerswitch won't forward to other (sub) networks this sort of broadcast
9. Address Resolution Protocol (ARP)
• ARP (corresponding MAC address )
• MAC ( physical address )
• IP ( logical address )
• Assigned by the ISP
ARP
RARP
10. Internet routing
• Called gateways
• Routing protocols is used by the routers to determine appropriate
path
• At application Layer protocol
• Two Types
• Interior routing ( neighboring )
• Rip: Routing Information Protocol (periodic updates)
• IGP: interior gateway protocol (fast convergence)
• OSPF: open shortest path first ( directly connected)
11. Exterior routing
• BGP : border gateway protocol (multithoming)
Also provide services
• Fragmentation
• Time outs ( specifies age )
• Options (mark packets)
12. ICMP : Internet Control Message Protocol
Purpose
To provide informational messages considering the routing of IP
datagram.
Two types of information messages
1- control messages
2-Error messages
14. TCP
Reliable transmission f information
Controls abnormality
Relies at (layer 4) of OSI model
Consist of 4 layers
15. Three way handshake
• The first (Host A) starts an connection by sending a data packets
with the initial number sequence (X) and SYN bit set to
demonstrate an association demand.
• The second (Host B) gets the SYN, records the acknowledging so as
to group number X, and SYN . (with an ACK = X + 1). Host B insert
its own initial sequence number (SEQ = Y). An ACK = 20 implies the
host has gotten bytes 0 through 19 and expects byte 20 next. This
strategy is called forward acknowledgment. Host A then recognizes
all bytes Host B sent with a forward acknowledgment showing the
following byte Host A hopes to get (ACK = Y + 1).
16. Internet Protocol
• Internet protocol is a system protocol at (layer 3)
• Contain addressing data
• Ip is connectionless service
• Best delivery of data
• Datagrams transfer measured through (MTU)
17. TCP SLIDING WINDOW
• A sliding window protocol is a feature of packet-based data
transmission protocols. Sliding window protocols are used where
reliable in-order delivery of packets is required, such as in the Data
Link Layer (OSI model) as well as in the Transmission Control
Protocol (TCP)
18. USER DATAGRAM PROTOCOL
• The User Datagram Protocol (UDP) is one of the core members of
the Internet protocol suite. The protocol was designed by David P.
Reed in 1980 and formally defined in RFC 768. UDP uses a simple
connectionless transmission model with a minimum of protocol
mechanism.
• Core member of IP
• Small packet size
• Does not guarantee packet delivery
20. THE APPLICATION LAYER
• The application layer is a layer in the Open Systems
Interconnection (OSI) seven-layer model and in the TCP/IP protocol
suite.
• It consists of protocols that focus on process-to-process
communication across an IP network
• It is service that provides communication application from one end
to another
• Provides a firm communication interface and end-user services
• Example: HTTP, FTP SMTP
21. DNS
• The Domain Name System (DNS) is a hierarchical distributed
naming system for computers, services, or any resource connected
to the Internet or a private network.
• It associates various information with domain names assigned to
each of the participating entities.
• www.google.com.
22. NETWORK SECURITY EXPATIATION AND THREATS IN
TCP/IP
• Data is very confidential an precious
• Business associations and government
• Data security
• Network Security
• Initial a safe system must have trusted and secured data against intruders
• Adjustments while in case of threats
• Accessibility of data to its essential beneficiaries
23. CERT
• CERT is an open association whose objective is to "study Internet
security vulnerabilities,
• Give episode reaction administrations to locales that have been the
casualties of assault
• Distribute an assortment of security alarms,
• Research in wide-territory arranged figuring, and create data and
preparing to enhance security
24. How attacker Attacks the data
1-Passive Reconnaissance
Passive reconnaissance is an attempt to gain information about
targeted computers and networks without actively engaging with the
systems.
2-Active Resonance
In active Reconnaissance in contrast, the attacker engages with the
target system, typically conducting a port scan to determine find any
open ports.
IF a system detects you , it can block your IP
25. Firewalls
• firewall is a network security system that monitors and controls the
incoming and outgoing network traffic based on predetermined
security rules
• Interconnects networks with differing trust
• Imposes restrictions on network services
• only authorized traffic is allowed
• Auditing and controlling access
• can implement alarms for abnormal behavior
• Provides perimeter defence
26. Firewalls
Characterized by protocol level it controls in
• Packet filtering
• Application gateways
• Combination of above is dynamic packet filter
27. Packet filtering
• Simplest of components
• Uses transport-layer information only
• Filtering with incoming or outgoing interfaces
• Permits or denies certain services
28. Application gateways
• Firewall runs set of proxy programs
• Proxies filter incoming, outgoing packets
• All incoming traffic directed to firewall
• All outgoing traffic appears to come from firewall
• Policy embedded in proxy programs
29. Intrusion Detection System (IDS)
• intrusion detection system (IDS) is a device or software application
that monitors network or system for malicious activities or policy
violations and produces reports to a management station
• IDS is used to recognize and alarm on malicious events that occur
within the networks.
• IDS arrangements are intended to screen occasions in an IT system,
hence supplementing the first line of defense (behind firewall)
against attacks