Summer Workshop on Cyber Security Computer Networks Security (Part 1) Dr. Hamed Mohsenian-Rad University of California at Riverside and Texas Tech University August 12- 16, 2013 Supported by National Science Foundation Overview of Computer Networks Our Goal: Get “feel” and terminology Focus on the Internet What is the Internet? What is the Protocol? Layered Network Architecture. Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 2 Overview of Computer Networks Our Goal: Get “feel” and terminology Focus on the Internet What is the Internet? What is the Protocol? Network Security Layered Network Architecture. Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 3 What is the Internet Millions of connected computing devices: • End systems / Hosts (Running Net Apps) • Communication Links (Wired or Wireless) • Routers and Switches (Forward “Packets”) mobile network global ISP home network regional ISP institutional network Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 4 What is the Internet Network of Networks • • • • ISPs Institutional Networks Home Networks Mobile Networks mobile network global ISP home network regional ISP Internet Protocols: • Control Sending & Receiving of Messages • E.g.: TCP, IP, HTTP, 802.11 institutional network Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 5 What is a Protocol? Human Protocol: • “What time is it?”, “I have a question.”, … Network Protocols: • Machines instead of humans. Protocols define format and order of messages sent and received among network entities, and actions taken on message transmission and message receipt. Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 6 What is a Protocol? Protocol define the interaction sequences over time: Hi TCP connection request Hi TCP connection response Got the time? Get http://www.awl.com/kurose-ross 2:00 <file> Time Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 7 Protocol Layers Networks are complex with many “pieces”: • • • • • • • • • Hosts Routers Wired Links Wireless Links Applications Protocols Hardware Software … Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 8 Protocol Layers Networks are complex with many “pieces”: • • • • • • • • • Hosts Routers Wired Links Wireless Links Applications Protocols Hardware Software … Q: How can we organize the structure of networks? Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 9 Example: Organization of Air Travel A series of steps are taken at different “layers” : ticket (purchase) ticket (complain) baggage (check) baggage (claim) gates (load) gates (unload) runway takeoff runway landing airplane routing airplane routing airplane routing Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 10 Example: Organization of Air Travel Each layer implements a “service”: Via its own “internal-layer” actions. ticket (purchase) ticket (complain) ticket baggage (check) baggage (claim baggage gates (load) gates (unload) gate runway (takeoff) runway (land) takeoff/landing airplane routing airplane routing airplane routing departure airport airplane routing airplane routing intermediate air-traffic control centers arrival airport Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 11 Internet Protocol Stack Application There are five layers in Internet Protocol Stack with different functionalities and protocols. Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 12 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 13 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 14 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 15 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process data transfer TCP, UDP Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 16 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process data transfer Transport TCP, UDP Network Link They all use TCP Protocol for “reliable” data transmission. (Socket Programming) (Each socket has a port #) Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU Physical 17 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process data transfer TCP, UDP Network: Routing from source to destination IP, Routing Protocols Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 18 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process data transfer TCP, UDP Network: Routing from source to destination IP, Routing Protocols Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 19 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process data transfer TCP, UDP Network: Routing from source to destination IP, Routing Protocols Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 20 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process TCP, UDP Network: Routing from source to destination data transfer IP, Routing Protocols Link: Routing from source to destination Transport Network Link Physical Ethernet, IEEE 802.11 (WiFi) Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 21 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process TCP, UDP Network: Routing from source to destination data transfer IP, Routing Protocols Link: Routing from source to destination Transport Network Link Physical Ethernet, IEEE 802.11 (WiFi) Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 22 Internet Protocol Stack Application: Supporting network apps FTP, HTTP, SMTP, Skype Application Transport: Process-to-process IP, Routing Protocols Link: Routing from source to destination TCP, UDP Network: Routing from source to destination data transfer Transport Network Link Physical Ethernet, IEEE 802.11 (WiFi) Physical: Bit-by-bit transmission Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 23 Packets Network communications are essentially 0-1 bit streams: But we break down bit streams to small bit chunks = packets. The packet at each layer: Can have different names (frame, segment, etc.) Can have different sizes Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 24 Packets Application Transport Network Link Physical Message Segment Datagram Frame Application Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 25 Packet Headers Protocol at each layer adds its own “headers” for “control data”. Application Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 26 Packet Headers Protocol at each layer adds its own “headers” for “control data”. Application Message Transport Network Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 27 Packet Headers Protocol at each layer adds its own “headers” for “control data”. Application Transport Network Segment Message HT Used by TCP and UDP Link Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 28 Packet Headers Protocol at each layer adds its own “headers” for “control data”. Application Transport Network Link Datagram Message HT HN Used by IP, Routing Physical Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 29 Packet Headers Protocol at each layer adds its own “headers” for “control data”. Application Transport Used by Ethernet, … Network Link Physical Message HT HN HL Frame Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 30 What is Next? For the rest of this track we will cover: Part 2: Common Tools & Techniques in Network Security (Dr. Akbar Siami-Namin) Part 3: Cyber Security in the Internet Protocol Stack (Dr. Hamed Mohsenian-Rad) Part 4: Research and Education in Network Security (Dr. Rattikorn Hewett) Summer Workshop on Cyber Security August 12- 16 , 2013 – Network Security, UCR & TTU 31