Saturday, June 24, 2017

Network Management

How does a proxy server defend clients on a private network?
How does DNS provide load-balancing services for an application?
At what layer of the OSI reference model do proxy servers works?

Explain the purpose and features of various network appliances

1.    The proxy server functions as an intermediary between the clients on the private network and the Internet by substituting its own registered IP address for the private IP addresses in the clients’ Internet service requests. The Internet servers then reply to the proxy server, and the proxy forwards the replies to the clients.
2.    When a DNS server is configured with resource records providing multiple IP addresses for a single server name, the server can respond to name resolution requests for that server with a different IP address each time. This enables each IP address to receive an approximately equal portion of the traffic intended for that server.
3.    Proxy servers operate at the application layer of the OSI model.

Can you answer these questions?

Find the answers to these questions at the end of this chapter.
1.    What is the term for a device that determines the length of a cable by transmitting a signal at one end and measuring how long it takes for a reflection of the signal to return from the other end?
2.    A continuity test of a newly installed UTP cable run with a wiremap tester indicates an open circuit on one of the wires. What would be the most likely cause for the problem?
3.    You are working on a CAT5 UTP network that is several years old. Over time, some of the paper labels the original cable installers used to identify wall plates and patch panel connectors have worn away or fallen off. As a result, there is some cable runs that you are unable to identify. After checking with your supervisor, you discover that the company has no cable testing equipment and is unwilling to hire a consultant just to identify cable runs. What is the most inexpensive tool you can buy to associate unlabeled wall plates with the correct patch panel ports?
4.    Which of the tools covered in this objective is only usable on analog connections?
5.  Which tool might you use to connect internal UTP cable runs to the keystone connectors that snap into wall plates?
Objective .2: Given a scenario, use appropriate hardware tools to troubleshoot connectivity issues
1.    A time domain reflectometer (TDR).
2.    The most likely cause is an incorrect punch down in one of the connectors. You would repair it by removing the cable from the connector and punching it down again.
3.    A tone generator and locator is the most inexpensive cable testing tool that can accomplish the desired task.
4.    A linesman’s handset or butt set is only usable on analog networks.
5.    You use a punch down tool to connect keystone connectors to cables.

Can you answer these questions?

Find the answers to these questions at the end of this chapter.
1.    Which TCP/IP tool uses ICMP messages and manipulates IPv Time to Live values to disclose the route packets take through an internetwork?
2.    Which utility can you use on a Windows computer to view resource record information on a particular DNS server?
3.    What Windows command line utility can you use to release an existing DHCP address lease and request a new one?
4.    Which two utilities can display a Windows computer’s routing table from the command line?

Given a scenario, use appropriate software tools to troubleshoot connectivity issues

1.    Traceroute.
2.    nslookup.
3.    Ipconfig.exe.
4.    Route.exe and Netstat.exe.

Can you answer these questions?

Find the answers to these questions at the end of this chapter.
1.    Which versions of the Simple Network Management Protocol do not include any security protection other than a clear text community string?
2.    What program was created to provide logging services for the UNIX sendmail program?
3.    What type of log does a web server maintain, recording all of the client visits and hits?
4.    What is the primary difference between a protocol analyzer and a network sniffer?

Objective .: Given a scenario, use the appropriate network monitoring resource to analyze traffic

1.    Version 1 and version 2c.
2.    syslog.
3.    A history log.
4.    Analyzers display information about each of the protocols involved in the creation of each packet, while sniffers look for trends and patterns in the network traffic.

Can you answer these questions?

Find the answers to these questions at the end of this chapter.
1.    Which Windows application would you most likely use to create a baseline of the system or network performance?
2.    What is the term usually applied to a graphical representation of network devices, automatically compiled, and containing information such as IP addresses and connection speeds?
3.    What is the reason for having a cable management policy?

Describe the purpose of configuration management documentation

1.    Performance Monitor.
2.    A network map.
3.    A cable management policy specifies how cable runs, wall plates, and patch panels should be labeled so that administrators can easily locate specific connections.

Can you answer these questions?

Find the answers to these questions at the end of this chapter.
1.    What is the term used to describe the DNS-based method of load balancing?
2.    Which of the two main QoS methods uses tags in the IP header to specify the priority of the data in the packet?
3.    What is the name of the protocol that enables proxy servers to exchange information among one another?
4.    Which type of QoS requires the use of a specialized protocol, such as the Resource Reservation Protocol (RSVP)?

Explain different methods and rationales for network performance optimization

1.    Round robin DNS.
2.    Differentiated services.
3.    The Cache Array Routing Protocol (CARP).
4.    Integrated services (IntServ).

grep CTF

I used grep grep -i -r "string" /directory  -i to accept lowercase and uppercase  -r recursive __ look for all fol...