1. COS 338 Day 20

2. 2 DAY 19 Agenda Assignment 6 Due Lab 7 due next Monday Assignment 7 Posted Due Dec 1 Capstone Progress reports due Exam 3 on November 21 Chap 8&9, open book, open notes, 60 min, 25 M/c questions. Quiz can be taken from anywhere. Availability, time and password will be sent via WebCT e-mail Today we will do discuss network management

3. Chapter 10 Copyright 2004 Prentice-Hall Panko’s Business Data Networks and Telecommunications, 5 th edition Network Management

4. Cost

5. 5 Figure 10-1: Network Demand Versus Budget Trends Money/ Demand Time User Demand Budget

6. 6 Figure 10-2: Cost Issues The Importance of Costs Exploding demand Slow budget growth Falling hardware costs help, but software costs fall more slowly, and labor costs are rising Select the least expensive technology that will fully meet user needs

7. 7 Figure 10-2: Cost Issues Non-Technology Costs Labor costs High, and unit labor costs are rising over time Rising Health Care costs are also a factor Often dominate total costs Carrier fees Recurring contractual charges

8. 8 Figure 10-2: Cost Issues Total Cost of Ownership Fully configured cost of hardware Base price plus necessary options Often much higher than base price Fully configured cost of software Initial installation costs Vendor setup costs IT and end-user labor

9. 9 Figure 10-2: Cost Issues Total Cost of Ownership Ongoing costs Upgrades Labor costs often exceed all other costs Immature products have very high labor costs Total cost of ownership (TCO): total of all costs over life span

10. 10 Figure 10-3: Multiyear Cost Analysis: Total Cost of Ownership (TCO) Year 1Year 2Year 3Year 4 $200,00015,000 Base Hardware 85,0009,000 Hardware Options Total 245,000 112,000 $100,00010,000 Base Software130,000 50,00010,000 Software Options80,000 435,00044,000 Technology Subtotal 567,000

11. 11 Figure 10-3: Multiyear Cost Analysis: Total Cost of Ownership (TCO) Note: The total cost of ownership is $1,142,000. Year 1Year 2Year 3Year 4 50,000Implementation 100,00075,000 Ongoing IT Labor Total 50,000 325,000 50,00025,000 Ongoing User Labor 125,000 275,000100,000 Labor Subtotal575,000 710,000144,000 Total1,142,000 Note: The total cost of ownership is $1,142,000. 75,000 Planning and Development 75,000

12. Network Simulation

13. 13 Figure 10-4: Network Simulation Simulation Build a model, study its implications More economical to simulate network alternatives than to build them Opnet GURU is a Simulation tool

14. 14 Figure 10-4: Network Simulation What is: the existing situation Net 1 Net 2 Net 3 Net 4 Net 5 Net 6 Utilization in Peak Hour 95% Too high!

15. 15 Figure 10-4: Network Simulation What-if: See the Impact of a Change Net 1 Net 2 Net 3 Net 4 Net 5 Net 6 Est. Utilization in Peak Hour 70% Added Router Added Link

16. 16 Figure 10-4: Network Simulation Simulation Purposes Comparing alternatives to select the best one Base case and sensitivity analysis to see what will happen if the values of variables were varied over a range (+ or –- a certain amount) Anticipating problems, such as bottlenecks Planning for growth, to anticipate areas where more capacity is needed

17. 17 Figure 10-4: Network Simulation Before the Simulation, Collect Data Data must be good Otherwise, GIGO (garbage in, garbage out) Collect data on the current network Forecast growth

18. 18 Figure 10-4: Network Simulation The Process (Based on OPNET IT Guru) Add nodes to the simulation work area (clients, servers, switches, routers, etc.) Specify the topology with transmission lines (including line speeds) Configure the nodes and transmission lines (IP Time-to-Live value, etc.) Add applications, which generate traffic data

19. 19 Figure 10-4: Network Simulation The Process Run the simulation for some simulated period of time Examine the output to determine implications Validate the simulation (compare with reality if possible to see if it is correct) What-if analysis Application performance analysis (OPNET ACE)

20. 20 Figure 10-5: OPNET IT Guru Node Template

21. 21 Figure 10-6: Configuring a Frame Relay CIR

22. 22 Figure 10-7: Configured Simulation Model

23. 23 Figure 10-8: What-If Analysis

24. IP Subnetting

25. 25 Figure 10-9: IP Subnetting DescriptionStep 32 Total size of IP address (bits) 1 Size of network part assigned to firm (bits) 2168 Remaining bits for firm to assign 31624 Selected subnet/host part sizes (bits) 48/86/1012/128/16 A firm is given its network size; it chooses its subnet size. Total is 32 bits, so big subnet size gives many subnets but few hosts.

26. 26 Figure 10-9: IP Subnetting DescriptionStep Possible number of subnets (2^N-2) 5 254 (2^8-2) 62 (2^6-2) 4,094 (2^12-2) 254 (2^8-2) Possible number of hosts per subnet (2^N-2) 6 254 (2^8-2) 1,022 (2^10-2) 65,534 (2^16-2) 4,094 (2^12-2) Subnet Calculator http://www.solarwinds.net/free/

27. 27

28. Directory Servers Store corporate information Hierarchical organization of content LDAP standard to access directory servers

29. 29 Figure 10-10: Hierarchical Directory Server Name Space University of Waikiki (O) CN=Waikiki Astronomy (OU) Staff Chun CN Brown Ext x6782 Directory Server with Hierarchical Object Structure Ochoa Routers CprSci (OU) Brown Faculty E-Mail Brown@waikiki.edu Business (OU) LDAP Request: Get e-mail.Brown.faculty. business.waikiki LDAP Response: Brown@waikiki.edu O=organization OU=organizational unit CN=common name LDAP=Lightweight Directory Access Protocol

30. Needed to set up new routers Needed to change operation of old routers Time consuming and an important skill Configuring Routers

31. 31 Figure 10-11: Cisco Internetwork Operating System (IOS) Command Line Interface (CLI) CommandComment Router>enable[Enter]Router> is the prompt. The “>” shows that the user is in non-privileged mode. Enables privileged mode so that user can take supervisory actions. User must enter the enable secret. All commands end with [Enter]. Enter is not shown in subsequent commands.

32. 32 Figure 10-11: Cisco Internetwork Operating System (IOS) Command Line Interface (CLI) CommandComment Router#hostname julia Prompt changes to “#” to indicate that user is in privileged mode. User gives the router a name, julia. julia#config t Enter configuration mode. The t is an abbreviation for terminal.

33. 33 Figure 10-11: Cisco Internetwork Operating System (IOS) Command Line Interface (CLI) CommandComment julia(config)#int e0 Prompt changes to julia(config) to indicate that the user is in configuration mode. User wishes to configure Ethernet interface 0. (Router has two Ethernet interfaces, 0 and 1.) julia(config-if)#ip address 10.5.0.6 255.255.0.0 User gives the interface an IP address and a subnet mask. (Every router interface must have a separate IP address.) The subnet is 5.

34. 34 Figure 10-11: Cisco Internetwork Operating System (IOS) Command Line Interface (CLI) CommandComment julia(config-if)#no shutdown This is an odd one. The command to shut down an interface is “shutdown”. Correspondingly, “no shutdown” turns the interface on. julia(config-if)# Ctrl-Z User types Ctrl-Z (the key combination, not the letters) to end the configuration of e0. julia(config)#int s1 User wishes to configure serial interface 1. (Router has two serial interfaces, 0 and 1.)

35. 35 Figure 10-11: Cisco Internetwork Operating System (IOS) Command Line Interface (CLI) CommandComment julia(config-if)#ip address 10.6.0.1 255.255.0.0 User gives the interface an IP address and subnet mask. The subnet is 6. julia(config-if)#no shutdownTurns on s1. julia(config-if)# Ctrl-ZEnds the configuration of s1. julia# router rip Enables the Router Initiation Protocol (RIP) routing protocol.

36. 36 Figure 10-11: Cisco Internetwork Operating System (IOS) Command Line Interface (CLI) CommandComment julia#disable Takes user back to non-privileged mode. This prevents anyone getting access to the terminal from making administrative changes to the router. julia>

37. Network Management Utilities

38. 38 Figure 10-12: Network Management Utilities Network management utilities are programs to help network managers administer the network Security Management tools can be used to make attacks Policies should limit these tools to certain employees and for certain purposes Firewalls block many network management tools to avoid attacks

39. 39 Figure 10-12: Network Management Utilities Host Diagnostic Tools Network Setup Wizard works most of the time; need tools if it does not Testing the connection Open a connection to a website using a browser Ping a host to see if latency is acceptable

40. 40 Figure 10-12: Network Management Utilities Host Diagnostic Tools Loopback testing and ipconfig/winipconfig Go to the command line Ping 127.0.0.1. This is the loopback interface (you ping yourself) For detailed information: ipconfig /all or winipconfig (older versions of Windows)

41. 41 Figure 10-12: Network Management Utilities Host Diagnostic Tools Checking the NIC in Windows XP Right click on a connection and select Properties Under the name of the NIC, hit the Configuration button The dialog box that appears will show you the status of the NIC It also offers a Troubleshooting wizard if the NIC is not working

42. 42 Figure 10-13: NIC Configuration Dialog Box

43. 43 Figure 10-12: Network Management Utilities Host Diagnostic Tools Packet capture and display programs Capture data on individual packets Allows extremely detailed traffic analysis Look at individual packet data and summaries WinDUMP is a popular packet capture and display program on Windows

44. 44 Figure 10-12: Network Management Utilities Command prompt>tcpdump www2.pukanui.com 7:50.10.500020 10.0.5.3.62030 > www2.pukanui.com.http: S 800000050:800000050(0) win 4086 7:50.10.500020 is the time 10.0.5.3.62030 is the source host (62030 is the port number) www2.pukanui.com.http is the destination host (HTTP) WinDUMP from Ch. 8a

45. 45 Figure 10-12: Network Management Utilities 7:50.10.500020 10.0.5.3.62030 > www2.pukanui.com.http: S 800000050:800000050(0) win 4086 S indicates that the SYN flag is set 800000050:800000050(0) Seq No and length Win 4086 is the window size (for flow control) is the option for maximum segment size (size of the TCP data field) WinDUMP from Ch. 8a

46. 46 Figure 10-12: Network Management Utilities 7:50.10.500030 www2.pukanui.com.http > 10.0.5.3.62030 : S 300000030:300000030(0) ack 800000051 win 8760 SYN/ACK from the webserver 7:50.10.500040 10.0.5.3.62030 > www2.pukanui.com.http:. ack 1 win 4086 ACK to finish 3-way open WinDUMP from Ch. 8a

47. 47 Figure 10-12: Network Management Utilities 7:50.10.500050 10.0.5.3.62030 > www2.pukanui.com.http: P 1:100(100) 7:50.10.500060 www2.pukanui.com.http > 10.0.5.3.62030 :. ack 101 win 9000 7:50.10.500070 www2.pukanui.com.http > 10.0.5.3.62030 :. 1:1000(999) 7:50.10.500080 10.0.5.3.62030 > www2.pukanui.com.http:. ack 1001 win 4086 WinDUMP from Ch. 8a

48. 48 Figure 10-12: Network Management Utilities Host Diagnostic Tools Traffic summarization Shows statistical data on traffic going into and out of the host EtherPeek is a popular commercial traffic summarization program

49. 49 Figure 10-14: EtherPeek Packet Capture and Summarization Program

50. 50 Figure 10-12: Network Management Utilities Host Diagnostic Tools Connection analysis At the command line, Netstat shows active connections This can identify problem connections Spyware running on Port 3290

51. 51 Figure 10-12: Network Management Utilities Route Analysis Tools To test the route to another host Ping tests gives the latency of a whole route Tracert gives latencies to router along the path Ping 275 ms Tracert 25 ms 75 ms 250 ms 225 ms 150 ms (Problem?)

52. 52 Figure 10-12: Network Management Utilities Network Mapping Tools To understand how the network is organized Discovering IP addresses with active devices Fingerprinting them to determine their operating system (client, server, or router) A popular network mapping program is Nmap (Figure 10-4)

53. 53 Figure 10-12: Network Management Utilities IP Range to Scan Type of Scan Identified Host and Open Ports

54. 54 Figure 10-16: Simple Network Management Protocol (SNMP) Simple Network Management Protocol (SNMP) Standard for managing remote devices in a network Collects information from remote devices to give the network administrator an overview of the network Optionally, allows the network administrator to reconfigure remote devices Potential for strong labor cost savings

55. 55 Figure 10-16: Simple Network Management Protocol (SNMP) Network Management Software (Manager) RMON Probe Managed Device Manager manages multiple managed devices from a central location

56. 56 Figure 10-16: Simple Network Management Protocol (SNMP) Network Management Software (Manager) Network Management Agent (Agent), Objects RMON Probe Network Management Agent (Agent), Objects Manager talks to an network management agent on each managed device

57. 57 Figure 10-16: Simple Network Management Protocol (SNMP) Network Management Software (Manager) Network Management Agent (Agent), Objects RMON Probe Network Management Agent (Agent), Objects RMON (remote monitoring) probe is a special agent that collects data about multiple devices in a region of in the network. It is like a local manager that can be queried by the main manager.

58. 58 Figure 10-16: Simple Network Management Protocol (SNMP) Management Information Base (MIB) Management Information Base (MIB) Management Information Base (MIB) Network Management Software (Manager) RMON Probe MIB stores data about devices. MIB on manager stores all. MIB on device stores local information

59. 59 Figure 10-16: Simple Network Management Protocol (SNMP) Management Information Base (MIB) Management Information Base (MIB) Management Information Base (MIB) Network Management Software (Manager) Simple Network Management Protocol (SNMP) RMON Probe Command (Get, Set, etc.) Response Trap

60. 60 Figure 10-17: SNMP Object Model SNMP Object Model The MIB database schema Defines objects (parameters) about which information is stored for each managed device SNMP System Objects System name System description System contact person System uptime (since last reboot) Management Information Base (MIB)

61. 61 Figure 10-17: SNMP Object Model SNMP IP Objects Forwarding (for routers). Yes if forwarding (routing), No if not Subnet mask Default time to live Traffic statistics Number of discards because of resource limitations Management Information Base (MIB)

62. 62 Figure 10-17: SNMP Object Model SNMP IP Objects (Continued) Number of discards because could not find route Number of rows in routing table Rows discarded because of lack of space Individual row data in the routing table Management Information Base (MIB)

63. 63 Figure 10-17: SNMP Object Model SNMP TCP Objects Maximum / minimum retransmission time Maximum number of TCP connections allowed Opens / failed connections / resets Segments sent Segments retransmitted Errors in incoming segments No open port errors Data on individual connections (sockets, states) Management Information Base (MIB)

64. 64 Figure 10-17: SNMP Object Model SNMP UDP Objects Error: no application on requested port Traffic statistics SNMP ICMP Objects Number of errors of various types Management Information Base (MIB)

65. 65 Figure 10-17: SNMP Object Model SNMP Interface Objects (One per Port) Type (e.g., 69 is 100Base-FX; 71 is 802.11) Status: up / down / testing Speed MTU (maximum transmission unit—the maximum packet size) Traffic statistics: octets, unicast / broadcast / multicast packets Errors: discards, unknown protocols, etc. Management Information Base (MIB)

66. Remote Switch and Router Management

67. 67 Figure 10-12: Network Management Utilities Remote Switch and Router Management Telnet Web interfaces SSH TFTP Saves money compared to traveling to device

68. 68 Figure 10-18: Telnet, Web Management, SSH, and TFTP Telnet Remotely log into managed device as a dumb terminal Poor security Weak password authentication Passwords are sent in the clear, making them vulnerable to sniffers No encryption of traffic

69. 69 Figure 10-18: Telnet, Web Management, SSH, and TFTP Web Interfaces Managed device contains a webserver Administrator connects to the managed device with a browser Can use SSL/TLS but typically does not

70. 70 Figure 10-18: Telnet, Web Management, SSH, and TFTP SSH Secure shell protocol Similar to Telnet but highly secure Widely installed on Unix computers (including Linux computers) Software must be added to Windows devices

71. 71 Figure 10-18: Telnet, Web Management, SSH, and TFTP TFTP Trivial File Transfer Protocol Similar to file transfer program but simpler Simple enough to implement on switches and routers Often used to download configurations to a switch or router from a server

72. 72 Figure 10-18: Telnet, Web Management, SSH, and TFTP TFTP No password is needed Can be used by hackers to download attack programs Poor security makes TFTP very dangerous

73. Traffic Management

74. 74 Figure 10-19: Traffic Management Methods Traffic Management Capacity is expensive; it must be used wisely Especially in WANs

75. 75 Figure 10-19: Traffic Management Methods Traditional Approaches Overprovisioning In Ethernet, install much more capacity than is needed most of the time This is wasteful of capacity Does not require much ongoing management labor

76. 76 Figure 10-19: Traffic Management Methods Traditional Approaches Priority In Ethernet, assign priority to applications based on sensitivity to latency In momentary periods of congestion, send high- priority frames through Substantial ongoing management labor

77. 77 Figure 10-19: Traffic Management Methods Traditional Approaches QoS Reservations In ATM, reserve capacity on each switch and transmission line for an application Allows strong QoS guarantees for voice traffic Highly labor-intensive Data gets the scraps—capacity that is not reserved for voice

78. 78 Figure 10-19: Traffic Management Methods Traffic Shaping The Concept Control traffic coming into the network at access switches Filter out unwanted applications Give a maximum percentage of traffic to other applications

79. 79 Figure 10-19: Traffic Management Methods Traffic Shaping Advantages and Disadvantages Traffic shaping alone reduces traffic coming into the network to control costs Very highly labor intensive Creates political battles (as do priority and QoS reservations to a lesser degree)

80. Topics Covered

81. 81 Topics Covered Cost Exploding demand, slow budget growth Hardware, software, labor costs Fully-configured hardware versus base prices Total cost of ownership: cost over entire life cycle Network Simulation Model the network on a computer Explore alternatives Cheaper than building alternatives

82. 82 Topics Covered IP Subnet Planning Organization is given its network part Divides remaining bits of IP address into subnet and host part Must balance number of subnets with hosts per subnet Directory Servers Hierarchical data storage LDAP

83. 83 Topics Covered Configuring Routers Time-consuming; important skill Cisco IOS is the dominant router operating system Command-line interface (CLI) Network Management Utilities Both network managers and hackers love them Host diagnostic tools. Is the connection working? 127.0.0.1 Windows XP: Connection Properties

84. 84 Topics Covered Network Management Utilities Packet capture and display programs Traffic summarization program (Etherpeek) Netstat to show active connections Route analysis: Ping and Tracert Network mapping tools (nmap)

85. 85 Topics Covered Simple Network Management Protocol (SNMP) Manager, managed devices, agents Get and set commands MIB RMON probe SNMP object model (MIB schema)

86. 86 Topics Covered Remote Switch and Management Utilities Saves money compared to traveling to device Telnet Web interfaces SSH TFTP

87. 87 Topics Covered Traffic Management Capacity is expensive on WANs Overprovisioning is too wasteful on WANs Priority is good but expensive to manage QoS reservations only allow strong guarantees for some services; rest get the scraps Traffic shaping: only select certain type of traffic Drop certain traffic or limit it to a certain amount