NETWORK + II Assignment Module 7
Harrison Valetski
October 27, 2015
NETWORK + II Assignment Module 7
As a network administrator, it's important that you know the devices that are connected in your network, their general capabilities, and what they are actually doing at any given moment. If you have been managing a network for a long while, this will generally be the case; but suppose you were "thrown in" to the position of network administrator in a network of which you had no prior knowledge. There would be many network monitoring tools from which you could choose to gather information about your network and to determine what had already occurred there before you were responsible.
Exam Essentials
Know the purpose of various network appliances A load balancer can create multiple paths for traffic and thereby allow the same session to use multiple physical links. This will result in greater throughput for the session. A proxy server is a device that makes a connection to a website on behalf of a user. It can be used for control and for detailed reporting. Content filters can be used to determine what traffic is allowed to flow into and out of a network. A VPN concentrator creates a secure tunnel between two devices using an encapsulation protocol such as PPTP or L2TP.
1. Discuss the purpose and features of a Content Filter, and a load Balancer.
Content filter
A content filter is a specialized device that can be configured to allow some types of traffic to flow through it while stopping the flow of other types of traffic. This type of content filtering is essential to organizations so that security and productivity can be maintained simultaneously. The biggest difference between the different types of content filters is the level of content they filter. For example, a layer 7 content filter can be configured to be much more selective than a layer 3 filter. In fact, layer 7 content filters can be configured to disallow access to websites that contain data or graphics that are not deemed acceptable by management standards. If a user tries to access a site that contains unacceptable graphics or data, the site will be disallowed not because of an IP address or hostname, or even port address, but because of the nature of the material on the site. This gives you much more granular control over users.
Load balancer
In today's networks, the resources that are essential for a user are often stored off the user's computer, sometimes in multiple locations for the same resource. When this is done, the user can gain access to the resources by going to a specific logical location, and the network devices can quickly decide how to obtain the user data and from which physical location to obtain the resource. This all occurs completely unbeknownst to the user. The device that makes all this magic happen is a load balancer.
Actually, a load balancer is as much a network role as it is a network appliance. Many devices can be configured to provide a load balancing function. Servers can be configured with multiple NICs and clustered together, routers can be configured with multiple associated interfaces or subinterfaces, and switches (such as the content switch mentioned earlier) can be configured to direct traffic and to change the physical location on each request. This is sometimes referred to as round robin since the physical connection just keeps going round and round. These types of load balancing techniques can dramatically improve the speed of the network for the user.
2. Discuss the purpose and types of SNMP software
Simple Network Management Protocol (SNMP) is a protocol that has been used by network administrators for more than 20 years to get information about the devices in their network. If you were using SNMP, you would be able to start getting the "big picture" of what is out there on your network. The general principle behind SNMP is that network components (such as computers, routers, and switches) can be installed with agent software that causes them to report information back to a central server installed with Management Information Base (MIB) software. The agents and MIB they report to are all said to be in the same community. You can configure agents to gather and report specified information such as type of device, processors, RAM, hard drive space, software installations, and so on, to the MIB that shares the same community name with the agents. This reporting of the agent is referred to as a trap. The commands that you use are generally get requests and set requests.
This might all sound like a great idea to help you learn about your network, but if you were to choose the first version of SNMP, there might be a problem. The problem with earlier versions of SNMP was that the information that was being gathered for the network administrator could also be read by an attacker. To address this issue, later versions of SNMP employ security measures such as encryption methods and integrity algorithms. Now let's examine a more secure version of SNMP.
SNMPv2 revises and improves the original SNMP. It includes enhancements in performance, security, and confidentiality of the network data. It remains backward compatible with the original version. Should you choose this version, you would be more secure than with SNMP, but why stop here?
Secure Network Management Protocol version 3 (SNMPv3) was developed in December 1997 to address even more security issues. It uses a secure authentication mechanism and encrypts data packets in transit. It also employs a message integrity algorithm to assure that the information that is sent to the administrator is accurate and has not been changed in transit. As you can see, this would be your best bet in today's security-conscious network. You could get the information that you need to understand your network better, while at the same time prevent the attackers from gaining information that you would rather they didn't have.
3. Describe network performance optimizations as it pertains to the following:
a. QoS
Quality of service (QoS) refers to the ability to provide different types of traffic flow with different types of service through the network. In other words, some types of traffic can receive priority and custom queuing through the network. This type of service is especially useful for video and voice applications that must maintain a consistent data flow in order to function properly. With good QoS, even a congested network can handle these types of applications.
b.Traffic shaping
Traffic shaping is controlling computer network traffic to optimize performance and/or reduce latency. This technology works to slow down some traffic flows that do not need all the bandwidth in the path they are using. In this way, it increases the available bandwidth for other traffic flows that need it. Traffic shaping uses bandwidth throttling, which is typically applied to specific connections on the network edges. Traffic shaping can also be applied to specific devices at the network interface card.
c. Load balancing
Today's networks often have multiple connections from a source to a destination. One of the reasons for this type of configuration is load balancing. When more than one path exists from a source to a destination, you can use each of the multiple paths to, in essence, "spread out" the traffic flows, thereby maximizing your available bandwidth on each connection. This is generally accomplished using routers or multilayer switches. Some of the most common types of traffic that are load balanced in today's networks include websites, FTP, DNS, and Internet Relay Chat.
d. High availability
High availability is a system design protocol that sets a limit on unplanned downtime during a given period of time. Organizations that manage significant amounts of money or even human lives will generally strive for very high availability for their computer systems and network connections. In some organizations, for example, one of the goals is to provide five nines uptime, which means that the system must be available 99.999 percent of the time. In other words, there can be no more than 0.001 percent of unplanned downtime. Since there are exactly 525,600 minutes in a year, this equates to 5.26 minutes per year (525,600 × .00001)!
Unplanned downtime is due to a network failure. Another type of downtime, referred to as planned downtime, includes maintaining and upgrading the network during periods of low traffic.
October 27, 2015
NETWORK + II Assignment Module 7
As a network administrator, it's important that you know the devices that are connected in your network, their general capabilities, and what they are actually doing at any given moment. If you have been managing a network for a long while, this will generally be the case; but suppose you were "thrown in" to the position of network administrator in a network of which you had no prior knowledge. There would be many network monitoring tools from which you could choose to gather information about your network and to determine what had already occurred there before you were responsible.
Exam Essentials
Know the purpose of various network appliances A load balancer can create multiple paths for traffic and thereby allow the same session to use multiple physical links. This will result in greater throughput for the session. A proxy server is a device that makes a connection to a website on behalf of a user. It can be used for control and for detailed reporting. Content filters can be used to determine what traffic is allowed to flow into and out of a network. A VPN concentrator creates a secure tunnel between two devices using an encapsulation protocol such as PPTP or L2TP.
1. Discuss the purpose and features of a Content Filter, and a load Balancer.
Content filter
A content filter is a specialized device that can be configured to allow some types of traffic to flow through it while stopping the flow of other types of traffic. This type of content filtering is essential to organizations so that security and productivity can be maintained simultaneously. The biggest difference between the different types of content filters is the level of content they filter. For example, a layer 7 content filter can be configured to be much more selective than a layer 3 filter. In fact, layer 7 content filters can be configured to disallow access to websites that contain data or graphics that are not deemed acceptable by management standards. If a user tries to access a site that contains unacceptable graphics or data, the site will be disallowed not because of an IP address or hostname, or even port address, but because of the nature of the material on the site. This gives you much more granular control over users.
Load balancer
In today's networks, the resources that are essential for a user are often stored off the user's computer, sometimes in multiple locations for the same resource. When this is done, the user can gain access to the resources by going to a specific logical location, and the network devices can quickly decide how to obtain the user data and from which physical location to obtain the resource. This all occurs completely unbeknownst to the user. The device that makes all this magic happen is a load balancer.
Actually, a load balancer is as much a network role as it is a network appliance. Many devices can be configured to provide a load balancing function. Servers can be configured with multiple NICs and clustered together, routers can be configured with multiple associated interfaces or subinterfaces, and switches (such as the content switch mentioned earlier) can be configured to direct traffic and to change the physical location on each request. This is sometimes referred to as round robin since the physical connection just keeps going round and round. These types of load balancing techniques can dramatically improve the speed of the network for the user.
2. Discuss the purpose and types of SNMP software
Simple Network Management Protocol (SNMP) is a protocol that has been used by network administrators for more than 20 years to get information about the devices in their network. If you were using SNMP, you would be able to start getting the "big picture" of what is out there on your network. The general principle behind SNMP is that network components (such as computers, routers, and switches) can be installed with agent software that causes them to report information back to a central server installed with Management Information Base (MIB) software. The agents and MIB they report to are all said to be in the same community. You can configure agents to gather and report specified information such as type of device, processors, RAM, hard drive space, software installations, and so on, to the MIB that shares the same community name with the agents. This reporting of the agent is referred to as a trap. The commands that you use are generally get requests and set requests.
This might all sound like a great idea to help you learn about your network, but if you were to choose the first version of SNMP, there might be a problem. The problem with earlier versions of SNMP was that the information that was being gathered for the network administrator could also be read by an attacker. To address this issue, later versions of SNMP employ security measures such as encryption methods and integrity algorithms. Now let's examine a more secure version of SNMP.
SNMPv2 revises and improves the original SNMP. It includes enhancements in performance, security, and confidentiality of the network data. It remains backward compatible with the original version. Should you choose this version, you would be more secure than with SNMP, but why stop here?
Secure Network Management Protocol version 3 (SNMPv3) was developed in December 1997 to address even more security issues. It uses a secure authentication mechanism and encrypts data packets in transit. It also employs a message integrity algorithm to assure that the information that is sent to the administrator is accurate and has not been changed in transit. As you can see, this would be your best bet in today's security-conscious network. You could get the information that you need to understand your network better, while at the same time prevent the attackers from gaining information that you would rather they didn't have.
3. Describe network performance optimizations as it pertains to the following:
a. QoS
Quality of service (QoS) refers to the ability to provide different types of traffic flow with different types of service through the network. In other words, some types of traffic can receive priority and custom queuing through the network. This type of service is especially useful for video and voice applications that must maintain a consistent data flow in order to function properly. With good QoS, even a congested network can handle these types of applications.
b.Traffic shaping
Traffic shaping is controlling computer network traffic to optimize performance and/or reduce latency. This technology works to slow down some traffic flows that do not need all the bandwidth in the path they are using. In this way, it increases the available bandwidth for other traffic flows that need it. Traffic shaping uses bandwidth throttling, which is typically applied to specific connections on the network edges. Traffic shaping can also be applied to specific devices at the network interface card.
c. Load balancing
Today's networks often have multiple connections from a source to a destination. One of the reasons for this type of configuration is load balancing. When more than one path exists from a source to a destination, you can use each of the multiple paths to, in essence, "spread out" the traffic flows, thereby maximizing your available bandwidth on each connection. This is generally accomplished using routers or multilayer switches. Some of the most common types of traffic that are load balanced in today's networks include websites, FTP, DNS, and Internet Relay Chat.
d. High availability
High availability is a system design protocol that sets a limit on unplanned downtime during a given period of time. Organizations that manage significant amounts of money or even human lives will generally strive for very high availability for their computer systems and network connections. In some organizations, for example, one of the goals is to provide five nines uptime, which means that the system must be available 99.999 percent of the time. In other words, there can be no more than 0.001 percent of unplanned downtime. Since there are exactly 525,600 minutes in a year, this equates to 5.26 minutes per year (525,600 × .00001)!
Unplanned downtime is due to a network failure. Another type of downtime, referred to as planned downtime, includes maintaining and upgrading the network during periods of low traffic.