Embedded Files
Planning & Design/Technical Development
This unit was essentially 4 assignments back to back, but as they had their planning and technical development combined, they are also combined on this page. It is split into the 4 units, and chronologically
Understanding Physical Address (MAC Addresses)
Network interface card with the Main controller chip, PCIE connector, and Ethernet port pointed out
Main Controller Chip:
Brains of the network card, routes the data from the ethernet to the PCIE connector while ensuring
reliability
PCIe Connector:
the standard for connecting to a computer. Allows
Fast, reliable data transfer over short distances
Ethernet Port: Plugs into the a RJ45 Cable, can send or or receive data
Mac Address:
Belongs to the NIC's main chip as that is the actual
brains of the NIC, allows identification of
manufacturer and is permanent
NIC with the sticker that shows the MAC address pointed out
The MAC address is considered the physical address because it is the only truly permanent identifier of a device. the IPs can be dynamically changed, but the MAC of one device will also belong solely to that device.
VM's: 16:98:77:e7:98:64
Physical: 04:92:25:51:BD:4C
On the physical NIC, the MAC address was assigned by the manufactorer as it was created. In contrast, the VM's was created by the press of a button. The only similarities between the two MAC's is that the OUI that use could not be Identified, which indicates that either the website is bad, or the NICs are too old/new/rare to be recorded. In differences though, the website indicated that the MAC of the real device was at the very least assigned from some manufacturer, while it had no information on the VM's MAC. a VM still needs a MAC address as it's goal is to recreate a real machine as realisitic to it as possible. Also, many network functions require the senders mac address to be a part of the packet, which would be an issue if it did not generate its own MAC to fake it.
Most of the vendors here were major companies. Additionally, most were making real NICs, with only the VMware being made up and maybe the last one too. Virtualization Vendors also need OUIs as without them a protection service like cloudflare would find any traffic really suspicious. They also would add credibility to a virtual machine, allowing it to be more like the real ones. This has helped to understand how every MAC address, although it is unique, still identifies manufactorer and gives flexibility for them to include more data.
16:98:77 e7:98:64
The OUI (first 3 pairs) shows the manufacturer of the NIC. As this was a randomized MAC on a VM, this actually had no manufacturer when checked. manufacturers must use unique OUIs to prevent any accidental ovelap, which can cause great issues with systems. by each manufacturer having different starts, and trusting them to check that none of the devices they make overlap.
for the device identifier (last 3 pairs) this is the part that makes it truely unique. Every one of these, while they might overlap with another device, they won't overlap another device + manufactorer combo. This is what ensures every device is truely its own. This is important for frame delivery, because this is the only true unique and constant address for a device on a network
In short, every device needs a globally unique mac address to have a reliable identifier that only will ever apply to one device
Understanding Logical Addressing (IPv4 and IPv6)
Research Question 1 – Why does every interface automatically have an IPv6 link-local
address?
Using reliable sources (ending in either .edu or .gov), write a short paragraph (4–6 sentences)
explaining:
• What an IPv6 link-local address is
An IPv6 link-local address is the IPv6 with a prefix. link-local indicates that all device share the same link. link in this case means that all devices access the internet through one source.
• Why it always starts with fe80::
Just like 192.168.4 on the IPv4, fe80:: is what a IPv6 will always begin with. Its reserved for local (link-local)
• What kinds of communication link-local addresses support
Link-local addresses support crucial local-link communications, most notably the Neighbor Discovery Protocol (NDP) for functions like address resolution and router discovery.
• Why they do not require a DHCP server or external configuration
They do not require a DHCP server or external configuration because they are only used for local communication, which must function immediately upon connection.
• Why every IPv6-enabled device automatically generates one
Every IPv6-enabled device automatically generates one immediately upon interface activation using Stateless Address Autoconfiguration (SLAAC).
Use your own words—do not copy text from your sources.
Research Question 2 – Why is IPv6 important for the future of networking?
Write another 4–6 sentence paragraph using your own wording explaining:
• Why IPv4 is no longer sufficient
IPv4 is 4 bytes, which comes out to around 4.3 billion unique combinations. With the fact that some of these are reserved and theres more devices then ever, we reached the limit on IPv4 devices.
• How IPv6 solves the address shortage
IPv6, instead of 4.3 billion combinations, is upwards of 100 quadrillion unique combinations. This allows every device to get its own, even with reserved ranges.
• What new capabilities IPv6 introduces (efficiency, security, mobility, routing improvements)
IPv6 introduces better security with mandatory IPsec support, improves routing efficiency with simplified headers and hierarchical addressing, and offers built-in mobility features and automatic address configuration.
• Why modern networks must support both IPv4 and IPv6 during the transition
Old devices made use IPv4, new use IPv6, theres a time (right now) where both are commonly used
3. Paragraph: Why Logical Addressing Exists
Write one paragraph (5–7 sentences) explaining:
Why do we need logical addresses (IP addresses) in addition to physical MAC addresses?
How do IP addresses allow communication beyond the local network?
Your explanation should refer to:
• Local vs. global communication
• How routers use IP addresses
• An example from your own experience (web browsing, gaming, email, etc.)
there is a need logical IP addresses in addition to physical MAC addresses because MAC addresses are only useful for local communication within a single network segment, whereas the hierarchical structure of an IP address is necessary for global communication across the internet. The IP address contains both a Network ID (for routing) and a Host ID (for the specific device), allowing devices to be located anywhere in the world. Routers are the key devices that use the Network ID portion of the destination IP address to consult their tables and decide the best path to forward the data packet across multiple interconnected networks. logical addressing allows my computer, which since the router was recently changed, is currently running on DHCP, to still work every time the system restarts.
IPv4 Vs IPv6 comparison table
Dynamic vs. Static Addressing & When to Use Each
VM1 IP address
VM 2 IP address
VM1
DHCP4: true
DHCP6:true
VM2
DHCP4:true
DHCP6: true
Network manager on VM2
nmcli device show in VM2
Looking at the two devices:
• Which VM uses which configuration tool(s)?
The old VM uses subiquity for the configuration, which upon search is a IT company. The newer VM is using NetworkManager, is using a standardized and open source recent library.
• Are both using DHCP for IPv4 or IPv6?
Since the new VM is more recent, it supports DHCP for both IPv4 and IPv6, while the older VM only supported DHCP for IPv4.
• Are the configuration syntaxes similar or different?
the actual configuration files, they are very similar, the only real difference being the new one includes dhcpv6: true and the mac address.
• Why might two Linux systems configure networking differently?
Linux systems might configure networking differently if one is built for security and reliability, while another is general "average" person use.
4. Comparing
The two VMS are configured the same way, but have some pretty major differences in that. Both use netplan for their link, but the newer basically passess off everything to network manager, and the older does it all itself. by looking on canonicals website, it described that the newer is basically just setting DHCP true for any active adapter (wifi/ethernet) on both IPv4 and IPv6
The Newer VM's compact netplan is above, while the olders netplan with a static address is below.
Task 2: Scenario Analysis (Static vs. Dynamic Addressing)
Now apply your understanding to real-world devices. You will decide whether each device should use static or dynamic addressing. Analyze the following:
1. A school web server
This device would probably use a static IP, as it needs to be constantly accessed by the students and teachers. It needs to be accessed easily, and if it had a dynamic IP it would be like a moving bookcase
2. A classroom printer
A printer would also probably use a static IP for the same reasons listed above
3. Student laptops
A laptop would use a dynamic IP, as it isn't being accessed enough by other devices on the network to need a dynamic one. Additionally, if it was all static there runs a risk of the network manager accidentally assigning 2 devices the same IP
4. Security cameras
A security camera could use either a dynamic or static IP, depending on how it works. If it reports its stream to a main server that then sends the video out to a client, it could be dynamic, and the server static. If it was directly streaming to the client, it would have to be static
5. A teacher workstation
A workstation could also go either ways, depending on if the teacher is doing anything where the students/other teachers are connected to their device. Probably, it would be fine to be dynamic, as its most likely behaving almost identical to a laptop, but static wouldn't hurt.
Configuring and Verifying IP Addresses on a Linux VM
The New Netplan
Applying the new netplan
Testing & Evaluation
Old Virtual Machine
1. DHCP for IPv4?
This Vm does use DHCP for IPv4. dhcp4:true shows this
2. DHCP for IPv6?
This VM does not use DHCP for IPv6. Theres no instance of dhcp6:true unlike the other VM and no other mentions of DHCP for ipv6
3. Configuration method
The old VM uses netplan. Its netplan is limited though, as it does not directly define DHCP for IPv6 or hand it off to another program (networkmanager) that does.
New Virtual Machine
1. DHCP for IPv4?
The new VM does support and use DHCP for IPv4, as shown through its dhcp4:true inside its netplan
2. DHCP for IPv6?
The new VM also supports and uses DHCP for IPv6, as shown through it using dhcp6:true inside its netplan aswell.
3. Configuration method
The New VM also uses netplan for the VM. It has both the general basic netplan, that does DHCP for everything in a compact 2 line statement, seen below.
network:
version: 2
renderer: NetworkManager
Further Reading: https://netplan.io/
The output of ip addr showing the staticly assigned ip
The output of ip route show showing the static ip as well as the routers ip
The ping failing, but pinging from the static ip
Upon failing the ping, the edited file was checked against a documented static ip file (found here https://netplan.io/ ), where it was slightly different order but identical in content (and the order was edited to be the same for extreme safety's sake), so it was not an issue with the file, and changing the IP to a slightly different number did not work either.
External connectivity with the static IP did not work. it is probabaly due to the fact that a random number was picked for the static IP, in a common range, and another device already had that IP, which means that the return packets would be sent to that original device and not mine. This is why static IPs are a kind of "high risk high reward", as they are necessary for some advanced networking but also require advanced understanding to use effectively.
Reflection
These assignments really went into the details of different types of addresses. Physical addresses, such as MAC, are unchanging addresses that are assigned at the factory. For logical addresses, such as IPs, it is dynamically (or statically) defined at runtime. The way it is defined is based on if DHCP (dynamic host configuration protocol) is used to give it a open IP as the device turns on, or a static slot is reserved for the device, that it always connects to. DHCP is better for larger networks where people really just can't be bothered for give a static IP for every device, and static IPs are also useful for any device that will constantly need to connect to other devices on the network, such as a printer or sharing to a smart tv. for the old and new VM, the older generally didn't have the most recent features like DHCP for IPv6. They are configured through netplans, which are YAML files that require very specific formatting, like 2 spaces between layers. In the real world, DHCP is used for virtually everything not making a connection over a long time to an outside source. One personal example is my home computer, which has a static IP address to allow for remote desktop to it from anywhere. If that fails, Zerotier is also used to forward the dynamic IP address to the laptop, to allow for it to still stream.
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