CS 560 Networks And Network Security JMU

Protocol Layering Sender Receiver Layer N . Layer N . Layer 2 Layer 1 Layer 2 Layer 1 Network Motivation for Protocol Layering The Programming Language Analogy Computer programming: Program -> Compiler -> Assembly Code -> Assembler -> Machi

Supernetting Recall: subnetting allows an organization to share a single IP network address among multiple physical networks Supernetting (a.k.a. classless addressing) allows the addresses assigned to an organization to span multiple IP network add

Error and Control Messages in the Internet Protocol Extranormal communication among routers and hosts is sometimes necessary to: Report errors Handle abnormal conditions Update routing information The Internet Protocol defines a single mechanis

Access Control for Networks Problems: Enforce an access control policy Allow trust relationships among machines Protect local internet from outsiders attempting to: Obtain information, modify information, disrupt communications Solution: fire

The Transmission Control Protocol (TCP) Application Services (Telnet, FTP, e-mail, WWW) Reliable Stream Transport (TCP) Unreliable Transport Service (UDP) Connectionless Packet Delivery Service (IP) The Transmission Control Protocol (TCP) TCP is a

Classless and Subnet Address Extensions (CIDR) Topics: There are problems with the IP addressing scheme weve studied Well study some ways to get around these problems Review: IP Addresses Problems with IP Addresses The designers of IP addresses

Intrusion Detection Systems We have already discussed: Host-based IDS Example: Tripwire Multihost-based IDSs examine data from a group of hosts Example: NIDES A network-based IDS analyzes network traffic (and possibly data from connected host

IP Routing Routing - the process of choosing a path over which to send packets Router - a computer that performs routing Routing is one of the Internet Protocols primary functions IP Routing Criteria that could (ideally) be used to make routing

The Internet Protocol (IP) Application Services (Telnet, FTP, e-mail, WWW) Reliable Transport Service (TCP) Connectionless Packet Delivery Service (IP) The Internet Protocol (IP) Provides a packet delivery service which is: Unreliable Best-effort