computer networks

Assignment 02 2

Assignment 02

Abstract

Assignment 02

Every layer in the open systems interconnection (OSI) model must work with its adjacent layer(s) to support the movement of information from one location to another (@talkb1nary, n.d.). If even one (of the seven) layers of the open systems interconnection (OSI) model malfunctions, then data cannot be received and/or delivered (@talkb1nary, n.d.). Therefore, a brief explanation of what the transport layer does is needed before discussing the network layer (Bonaventure, 2014). The transport layer is responsible for allowing software programs to: send and/or receive information (Bonaventure, 2014). With that said, the network layer has subnetworks; the transport layer indirectly works with these subnetworks (Bonaventure, 2014). The primary purpose of the network layer is to permit a multitude of networks to communicate with one another by using routers (Bonaventure, 2014). Routers are tools that work within the network layer to ensure that data packets are properly directed to their respective destinations (Bonaventure, 2014).

As far as network layer protocols are concerned, the most common network layer protocol is the internet protocol (IP) for the transmission control protocol/internet protocol (TCP/IP) model (Bonaventure, 2014). The purpose of the internet protocol (IP) is to provide rules to dictate how the information from the data link layer is translated (into a specific format on the network layer) so that the transport layer can carry out its own objective(s) (Bonaventure, 2014). Nowadays, there are two versions of the internet protocol (IP); the two versions of the internet protocol (IP) are: internet protocol version four (IPv4) and internet protocol version six (IPv6) (Bonaventure, 2014). Internet protocol version four (IPv4) is utilized to recognize equipment on a network by assigning each piece of equipment its own address (Beal, 2017). Although dwindling in popularity, internet protocol version four (IPv4) is still utilized today (Beal, 2017). With only a thirty-two-bit address length, internet protocol version four (IPv4) can only have about four billion address combinations (Beal, 2017). Therefore, internet protocol version four (IPv4) will slowly become obsolete (Beal, 2017). With that said, internet protocol version six (IPv6), which was being created during the 1990’s, will eventually replace internet protocol version four (IPv4) (Beal, 2017).

There are a multitude of advantages that internet protocol version six (IPv6) has over internet protocol version four (IPv4); two of the many advantages that internet protocol version six (IPv6) has over internet protocol version four (IPv4) are: volume and simplicity (Beal, 2017). As previously stated, one major problem with internet protocol version four (IPv4) is that the structure of this internet protocol version limits the volume of devices that can connect to the internet to about four billion (Beal, 2017). Instead of the thirty-two-bit address length of internet protocol version four (IPv4), internet protocol version six (IPv6) has a one hundred and twenty-eight-bit address length which allows for a higher volume of address combinations (Beal, 2017). Another advantage that internet protocol version six (IPv6) has over internet protocol version four (IPv4) is that the format of the header is more simplistic (Beal, 2017). The following screenshot provides a depiction of the internet protocol version four (IPv4) header versus the simplicity of the internet protocol version six (IPv6) header (Mukherjee, n.d.) ...

Whether an internet protocol (IP) address is: in an internet protocol version four (IPv4) format or in an internet protocol version six (IPv6) format, an internet protocol (IP) address is a one of a kind address that is associated to a specific piece of equipment that utilizes the internet (IP Location, n.d.). There are two main types of internet protocol (IP) addresses; the two main types of internet protocol (IP) addresses are: public internet protocol (IP) addresses and private internet protocol (IP) addresses (IP Location, n.d.). Public internet protocol (IP) addresses are: catalogued to ensure that there are no duplicates and visible to all (IP Location, n.d.). Information that is sent to a public internet protocol (IP) address will only get as far as the modem of a specific local area network (LAN); from there, the information is routed to a private internet protocol (IP) address that is associated to a specific piece of equipment (IP Location, n.d.). The following screenshot provides a depiction of the ranges of addresses that private internet protocol (IP) addresses can have (IP Location, n.d.) ...

Please note that the different classes for private internet protocol (IP) addresses allow for various amounts of private internet protocol (IP) addresses to be generated (as needed) (IP Location, n.d.). For most households and small businesses, class c private internet protocol (IP) addresses provides a sufficient range/amount of possible private internet protocol (IP) addresses (IP Location, n.d.). Larger businesses/organizations might need a greater volume of possibilities for private internet protocol (IP) addresses, and therefore would utilize private internet protocol (IP) addresses in the range of either class b private internet protocol (IP) addresses or even class a private internet protocol (IP) addresses (IP Location, n.d.). Aside from the two main types of internet protocol (IP) addresses (public internet protocol (IP) addresses and private internet protocol (IP) addresses), there are also a loopback internet protocol (IP) addresses (IP Location, n.d.). The purpose of a loopback internet protocol (IP) address is to examine if a network software algorithm is functioning properly (IP Location, n.d.).

On another note, the functionality of the network layer can be tested on a multitude of applications; the software package that will be discussed (to test the functionality of the network layer) is the command prompt (Microsoft Ping, 2012). One of the many commands that the command prompt software can execute is the ping command (Microsoft Ping, 2012). The purpose of the ping command is to diagnose the status of the connection at the internet protocol (IP) level (Microsoft Ping, 2012). If a ping command is executed, then a signal is sent to a sender’s internet protocol (IP) address to see if a reply will be received (Microsoft Ping, 2012). Another command that the command prompt software can execute is the ipconfig command (Microsoft Ipconfig, 2012). The purpose of the ipconfig command is to show the present configuration of the internet protocol (IP) on the computer network (Microsoft Ipconfig, 2012). With that said, the command prompt software can also execute a tracert command (Fisher, 2018). A tracert command displays information about the path that a specific piece of information took to travel from the sender to the receiver; this command prompt command can determine the number of stops/redirects that occur when data is sent from the sender to the receiver (Fisher, 2018). The last command that the command prompt software can execute (that will be discussed in this assignment) is the netstat command (Microsoft, 2009). The purpose of the netstat command is to display all operating transmission control protocol (TCP) that are connected to the computer network (Microsoft, 2009). With that said, the remainder of this assignment will focus on the analysis of a sample of data that was collected by the Wireshark software application (Combs, Harris, & Ramirez, 2018).

1. What field does indicate if it IPv4 vs IPv6?

The “Internet Protocol Version 4” and/or “Internet Protocol Version 6” fields indicate if it is IPv4 or IPv6. Please refer to the following screenshot(s) (Combs, Harris, & Ramirez, 2018)…

SPACE

SPACE

Search “ip” for Internet Protocol Version 4 data packets and “ipv6” for Internet Protocol Version 6 data packets in Wireshark (Combs, Harris, & Ramirez, 2018).

· Is that on the data link or network layer?

“IPv4/IPv6” is on the network layer (@talkb1nary, n.d.).

· Is the frame different depending if it IPv4 or IPv6?

The frame is different depending if it IPv4 or IPv6 (Combs, Harris, & Ramirez, 2018). Please refer to the following screenshot(s) (Combs, Harris, & Ramirez, 2018)…

Internet Protocol Version 4 has “Frame 2” whereas Internet Protocol Version 6 has “Frame 3” (Combs, Harris, & Ramirez, 2018).

2. Perform a "ping" command and locate on the capture.

Please refer to the following screenshot(s) (Microsoft Ping, 2012) and (Combs, Harris, & Ramirez, 2018)…

SPACE

· What's the payload of the "ping" packet? Is the payload important?

The payload of the "ping" packet is 32 bytes (Combs, Harris, & Ramirez, 2018). The payload is important because fragmentation can occur if the payload is greater than 1472 (Combs, Harris, & Ramirez, 2018). Please refer to the following screenshot(s) (Combs, Harris, & Ramirez, 2018)…

· Does the "ping" response have a payload? Is the payload important?

The "ping" response has a payload of 32 bytes. The payload is important because fragmentation can occur if the payload is greater than 1472 bytes (Combs, Harris, & Ramirez, 2018). Please refer to the following screenshot(s) (Combs, Harris, & Ramirez, 2018)…

· Can you determine all the "pings" based on the TTL number?

One cannot determine all of the "pings" based on the TTL (time to live) number (Combs, Harris, & Ramirez, 2018). The TTL (time to live) number varies from 1-254 based on the capture for file “Ping-Tracert(198 total)” (Combs, Harris, & Ramirez, 2018).

3. What IP address have flags?

Internet protocol (IP) addresses (with an internet protocol version four (IPv4) header format) will have flags (Mukherjee, n.d.).

· Demonstrate them.

Please refer to the following screenshot(s) (filtered by “ip.flags == 0x0000”) (Combs, Harris, & Ramirez, 2018)…

4. Are there any IP address fragmented on the capture?

There are IP address fragmented on the capture (Combs, Harris, & Ramirez, 2018).

· Demonstrate them.

Please refer to the following screenshot(s) (filtered by “ip.flags == 0x0000”) (Combs, Harris, & Ramirez, 2018)…

· Why fragmented? Assumptions? Facts?

As previously stated, fragmentation can occur if the payload is greater than 1472 bytes (which is what happened in this case) (Combs, Harris, & Ramirez, 2018).

5. Which IP version is the one that the capture has the most (IPv4 or IPv6)

There are significantly more internet protocol version six (IPv6) than internet protocol version four (IPv4) (Combs, Harris, & Ramirez, 2018).

· Demonstrate and provide details

Please refer to the following screenshot(s) (Combs, Harris, & Ramirez, 2018)…

As previously stated, internet protocol version four (IPv4) is still utilized today but internet protocol version four (IPv4) is dwindling in popularity (Beal, 2017).

6. While capturing, perform and locate the following traffic produced by performing the following commands:

· ping

Please refer to the following screenshot(s) (Microsoft Ping, 2012) and (Combs, Harris, & Ramirez, 2018)…

SPACE

· tracert

Please refer to the following screenshot(s) (Fisher, 2018) and (Combs, Harris, & Ramirez, 2018)…

SPACE

7. Identify and classify IP addresses by class if IPv4 or by other methods if IPv6

Please refer to the following screenshot(s) (Combs, Harris, & Ramirez, 2018)…

8. From the capture, can you identify the subnet mask of the network(s)

· Explain and Demonstrate

Please refer to the following screenshot(s) (filtered by “ip.addr == 192.0.2.1/8”) (Combs, Harris, & Ramirez, 2018)…

Conclusion

The Wireshark software package has a vast amount of functions (Combs, Harris, & Ramirez, 2018). Additional training and insight into computer networks is ever more vital as computer networks become ever more complex (Tanenbaum, 2011). An understanding of the details of each component in a computer network will lead to a greater understanding of the entire computer network (Tanenbaum, 2011).

Reference(s)

@talkb1nary. (n.d.). Layer 3 Network Layer. Retrieved October 30, 2018, from https://osi-

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Beal, V. (2017, October 27). What is The Difference Between IPv6 and IPv4? Retrieved October

30, 2018, from https://www.webopedia.com/DidYouKnow/Internet/ipv6_ipv4_

difference.html

Bonaventure, O. (2014, February 25). Computer Networking : Principles, Protocols and

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network/network.html

Combs, G., Harris, G., & Ramirez, G. (2018). Wireshark User’s Guide Version 2.9.0. Retrieved

October 20, 2018, from https://www.wireshark.org/docs/wsug_html/

Fisher, T. (2018, April 24). Tracert Command Tracert command examples, switches, and more.

Retrieved October 30, 2018, from https://www.lifewire.com/tracert-command-2618101

IP Location. (n.d.). What is an IP Address? Retrieved October 30, 2018, from

https://www.iplocation.net/ip-address

Microsoft. (2009, September 10). Netstat. Retrieved October 30, 2018, from

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-xp/bb490947(v=technet.10)

Microsoft. (2012, July 17). Ipconfig. Retrieved October 30, 2018, from https://docs.microsoft.

com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc940124

(v=technet.10)

Microsoft. (2012, July 17). Ping. Retrieved October 30, 2018, from https://docs.microsoft.com/

en-us/previous-versions/windows/it-pro/windows-2000-server/cc940091(v=technet.10)

Mukherjee, A. (n.d.). IPv6 Subnetting - How and Why to Subnet IPv6. Retrieved November 3,

2018, from http://www.firewall.cx/networking-topics/protocols/877-ipv6-subnetting-how-to-subnet-ipv6.html

Tanenbaum, A. S., & Wetherall, D. J. (2011). Computer Networks (5th ed.). Boston: Pearson

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