1. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Tom Davis, CISSP University IT Security Officer Office of the Vice President for Information Technology Computer Networks & Firewalls

2. University IT Security Office - http://www.itso.iu.edu/ Agenda Networks Firewalls Software Configuration Questions

3. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ A Word of Warning! Computer geeks love TLA’s And, I’m a computer geek! So, ask questions at anytime…

4. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Agenda Networks Firewalls Software Configuration Questions

5. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Network Internet Computer AComputer B

6. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Networking Terms IP addresses and DNS names –static vs. dynamic IP addresses Port numbers TCP vs. UDP

7. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ IP Addresses and DNS Names (Static IP Address) Internet 129.79.146.56 peppsi.geology.indiana.edu 165.139.69.1 nlcs.k12.in.us IP = Internet Protocol DNS = Domain Name System

8. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ IP Addresses and DNS Names (Dynamic IP Address) Internet 129.79.146.56 peppsi.geology.indiana.edu 165.139.69.3 dynamic-69-3.k12.in.us

9. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ IP Addresses and DNS Names (Dynamic IP Address) Internet 129.79.146.56 peppsi.geology.indiana.edu 165.139.69.3 dynamic-69-3.k12.in.us 165.139.69.7 dynamic-69-7.k12.in.us

10. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Port Numbers 165.139.69.1 (nlcs.k12.in.us) Port 80 Port 1568 web scream

11. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ TCP vs. UDP TCP (Transmission Control Protocol) –delivery is guaranteed (registered letter) –both endpoints are connected UDP (User Datagram Protocol) –delivery is not guaranteed (postcard) –both endpoints are not connected

12. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Agenda Networks Firewalls Software Configuration Questions

13. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Firewalls Purpose –block network connections, primarily based on: IP address Port number Protocol (TCP or UDP) Masquerading Firewalls –Network Address Translation (NAT)

14. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Firewalled Network Internet Firewall Protected Network 129.79.146.56 peppsi.geology.indiana.edu 165.139.69.1 nlcs.k12.in.us

15. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Masquerading Firewall Internet 165.139.69.2 firewall.k12.in.us Protected Network 129.79.146.56 peppsi.geology.indiana.edu 192.168.1.1 hidden.k12.in.us

16. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Agenda Networks Firewalls Software Configuration Questions

17. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Software Configuration IP Address and DNS Name –peppsi.geology.indiana.edu –129.79.146.56 Ports –1568 (recommended) Protocols: –Your machine sends data to IU via UDP –IU requests data from your machine via TCP

18. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Software Issues Dynamic IP addressing IP address blocking Port blocking Protocol blocking (TCP and UDP) Address masquerading

19. Computer Networks & FirewallsUniversity IT Security Office - http://www.itso.iu.edu/ Questions?