Eli5 vlan

Eli5 vlan

Labporn Diagrams Tutorials News. Please see the full rules page for details on the rules, but the jist of it is:.

How VLANs Work - Network Fundamentals Part 12

Post about your homelab, discussion of your homelab, questions you may have, or general discussion about transition your skill from the homelab to the workplace. Before posting please read the wiki, there is always content being added and it could save you a lot of time and hassle.

Feel like helping out your fellow labber? Contribute to the wiki! It's a great help for everybody, just remember to keep the formatting please. All experience levels. Try to be specific with your questions if possible. Might be able to find things useful for a lab. I have a modem, OnHub router, and a small switch because my router only has one port, and that's about the extent of my knowledge.

Everything in my house is either connected over wifi or connected to the unmanaged? I just got an old Thinkstation from work that I intend on making a server for a handful of services, and figure now is a good time to level up my network.

Unfortunately, I am basically braindead when it comes to networking understanding.

I understand pfsense is a firewall? But isn't my router also one, why do I need an extra one? I've also heard it manages VLANs -- but I have no idea what that is with a vague guess that it makes a different block of ips in my network? Before you fuck up your home network, I strongly encourage you to learn more about networking in general. You don't need a firewall, you don't need VLANs, etc.

If you want them, then there must be a reason why. If there is no reason why, then you should start by making test networks completely separate from your own network.

It's much easier to fix an issue when you can Google it. This is how I learn, I just jump in to something and flail around until I start to make connections. Worst case scenario I know I can just tear down and hook my router up to my modem again, but I will be careful. If you want to jump in at the deep end set up a separate network entirely. This allows you to do what ever you want without risking you home network.More details on the rules may be found in the wiki.

Please check out our Frequently Asked Questionswhich includes lists of subreddits, webpages, books, and other articles of interest that every sysadmin should read! Checkout the Wiki Users are encouraged to contribute to and grow our Wiki. So you want to be a sysadmin? Official IRC Channel - reddit-sysadmin on irc. The relay knows which network the request came from and it forwards the request including its own gateway address in that network. The server uses that to determine which scope to allocate an address from.

You add those scopes Just to clarify With the superscope configured, DHCP would hand out all of the addresses in Scope1, and then move on to the addresses from Scope2. The DHCP server sees this and matches it to the correct scope. It'll figure out which scope to assign from. Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

All rights reserved. Want to join? Log in or sign up in seconds. Submit a new text post. Get an ad-free experience with special benefits, and directly support Reddit. Do not expressly advertise your product. Welcome to Reddit, the front page of the internet.

Become a Redditor and join one of thousands of communities. How do the VLANs know where to get the address and which scope to use?

Want to add to the discussion? Post a comment! Create an account. Don't forget to configure your switch es to carry the VLAN traffic :.Make sure to read the rules! This subreddit is for asking for objective explanations. It is not a repository for any question you may have. LI5 means friendly, simplified and layperson-accessible explanations - not responses aimed at literal five-year-olds. Perform a keyword search, you may find good explanations in past threads.

You should also consider looking for your question in the FAQ. I really don't get them. So I am studying communication between machines and I have to design this I really don't get vlans. It leaves me dumbfounded, feeling like an idiot. So basically what a VLAN is, is just a concept: that different Layer2 networks exist on the same switch, or the same layer 2 network between switches. But to really understand them, you need to know how it works.

So in effect, you'll convert your ports into checkpoints: a trunk is like border police, it will allow only the frames tagged with configured VLANs to pass in both direction, but will not remove their tag, so they can be identified later on, as well. This port type is usually used between switches.

An access port is like a body guard on your doorstep "right before the client", which only allows frames tagged with configured VLANs to pass but tears their tag before they get to the client, because they won't be needing it anymore. Say you have three different switches Switch 1, 2, and 3. Each switch has four ports.

You decide to put switch 1 in the lobby. People plugging into the switch only have four ports from which to choose. Now, let's say you're tired of dealing with three separate switches and decide to get a single switch that has 12 ports.

You still want to maintain the idea of having "three" separate switches. If you were to put this new port switch in the lobby note: in real life, this would pose a major security riskpeople now have 12 ports from which to choose.

How do people know which port connects to what Switch 1 previously connected to? VLANs to the rescue. Now you have the virtual equivalent of three separate switches using a single piece of hardware. How do switches perform this seemingly magic trickery?Make sure to read the rules!

This subreddit is for asking for objective explanations. It is not a repository for any question you may have. LI5 means friendly, simplified and layperson-accessible explanations - not responses aimed at literal five-year-olds.

Perform a keyword search, you may find good explanations in past threads. You should also consider looking for your question in the FAQ. Dunno why this is getting downvoted, but thank you to everyone who has replied. This has helped my understanding of the subject very much! All the ports assigned to a specific VLAN act as if they were a completely independent switch. Each VLAN will typically have a unique subnet associated with it, but not always.

Trunking allows switches to exchange packets from different VLANs via a single port. So instead of needing a unique uplink cable for each VLAN on a switch you can instead have a single or group of Trunk ports that can send and receive packets for multiple VLANs.

On Trunks packets are 'tagged' with the associated VLAN information as they leave the switch via a trunked port and the receiving switch uses that tag to associate the packet with the correct VLAN. So like if device A port1 wanted to communicate with Device Z port 23 then we would need to use port 24 as trunking to allow this communication? I'm seeing trunking as like a cable between the two VLANs, if that makes sense.

So it trunking just routes data through VLANs, right? VLANs are where a network switch pretends to be multiple switches. Groups of switch ports are isolated from others so that no traffic passes between them. Each group of ports is a Virtual Local Area Network. Trunking is where the VLANs on one switch can also be made available at other switches. You could have two switches at different locations each with ports on multiple different VLANs and ports on the same VLAN would communicate as expected, even if they were on different physical switches.

Sometimes switches like this are connected by a simple trunking cable or fibre but networking protocols exist to allow trunking to travel over complex network links. VLANs allow switches to separate computers onto different networks without changing the physical setup and trunking is just a trick to spread these VLANs across multiple switches. Say you have HR, account, sales, and engineering and you want them all on separate networks for security reasons. If you have people spread out amongst buildings, you'd have to have separate switches and fiber runs and infrastructure for each network.

That makes sense. I hate networking These packet tracers help with the concept, but ELI5 helped more ha. Yes, you can give multiple racks the same networking, logically at least. Capacity on custom daisy-chain cables is often higher than a simple Ethernet trunking link so performance will often be less between remote switches.

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What do I need to know about setting up VLANs?

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VLAN vs Subnet: What Are Their Differences?

Basically, i've never seen or touched a PVID setting before, over the last 75 switches or so i've used. So why, on my nice shiney new HP G switches do i need to configure a PVID setting even though I've set the port in question to be untagged on its specific vlan? The PVID differed from the untagged vlan id in this instance, which completely confused me. The switch even tries to explain this to me with a helpful yellow "? I should add The reverse is also true.

You can egress an untagged frame from traffic on the PVID vlan while also egressing other types of tagged frames. PVID tells the switch how to handle untagged ingress frames, which broadcast domain they should be forwarded to. They produced that thing before they acquired anything and before switching up their naming scheme. Well yes, but most likely bought from some random Chinese manufacturer with HP stickers and visible parts of the firmware. Thank you! That makes more sense than the other explanations i've read i think.

Will i learn about this in more detail doing a CCNA course per chance? I started self learning last year but that's since been postponed due to having a baby :p. Yes but it's called native vlan for Cisco not pvid.

There isn't much to learn outside of what the top guy said. Maybe this is a CLI context thing? For example, Cisco lets you enter commands that are essentially no-ops: switchport access vlan 10 is meaningless on an interface that's been configured with switchport mode trunk. I've been driven a little crazy by unfamiliar switching platforms which have both an untagged and a PVID lever when I wanted to pass both tagged an untagged traffic over the same interface.

In this instance i had a port set to untagged vlan 14, with tagged vlan 22 and 23, but the PVID stayed set to vlan 7, which was the vlan all the ports were set to untagged initially on the switch when i began configuring it. So when all ports only had one untagged vlan, the PVID changed with it, but as soon as i changed that one port to a hybrid port and tagged other vlans on to it as well as changing the untagged vlan to one that differed to the rest of the switch, the PVID then didn't change.

So is this something to do with the way hybrid ports work? The terminology of "hybrid" is also fairly new to me with these new switches, but this seems to be a good learning experience.

Then there is the combo where you allow both untagged frames AND tagged frames at the same time. In this case you most likely have both a vlan configuration of which vland id's are expected to ingress and egress along with an allowed vlan list regarding ingress traffic. Now for the untagged traffic you must assign it to an internal vlan. By default this is vlan 1 which is why vlan 1 is bad since it by default unless configured otherwise could bypass your networkdesign.


Comware lingo is to call an interface who accepts both untagged AND tagged frames at the same time as "hybrid". However Comware have taken this some steps further where you based on ethertype also when using hybrid interface can assign different vlans to different ethertypes. So that IPv4 traffic is considered to be in one vlan and IPv6 traffic in another.

This way if incorrectly handled they will end up in a vlan where only the client interface itself is the only member of. I'm Cisco trained but have been supporting Dell for 8 months now. That really helped me understand their craziness. I agree that they sound like they should be the same thing. Any idea why they're separate knobs?VLAN and Subnet are both developed to deal with segmenting or partitioning a portion of the network.

And they also share such similarities as restricting broadcast domains or ensuring security through isolation of different sub-networks. However, there are obvious differences between them on operation, functionality and deeper objectives. Subnet is a small network composed by a group of IP addresses. It is part of a larger network. Any IP address within the same Subnet can communicate with each other without using routing devices.

To be clear, we can think Subnet as the department of a company, people in the same department can talk freely without going out of their department. If you want to reach an address outside of your Subnet, you will have to go through a router or modern Gigabit Ethernet switch with router functionality. Since Subnet is related to IP address, it often works at layer 3. Basically, VLANs are used at layer 2 to break up broadcast domains. VLAN and Subnet both have their advantages and limits.

However, if a network sniffer is employed, users from one Subnet can discover the existence of other Subnets, this will not happen to users of different VLANs. Fiber Transceiver Solution. Skip to content. Posted on July 11, by Admin. Subnet is an IP address range of IP addresses that help hosts communicate over layer 3. A Subnet is determined by the IP you use and the IP can be chosen by the admin of a computer or device.

VLANs perceived to be more secure and provide more robust control for the network. VLAN is extremely flexible, it brings better work performance, less traffic, and more efficiency. A Subnet will not be affected when other Subnets going down or having technical breakdowns. Bookmark the permalink. Share this page Share. Search for:. Proudly powered by WordPress. VLAN allows us to create different logical and physical networks.

Subnet allows us to create logical networks through the same physical network.Thank you for taking the time to respond. Was this article helpful? For a basic introduction to virtual local area networks VLANssee the following knowledge base articles:.

VLAN configuration mistakes can cause serious connectivity and security problems on your network. If you do not have experience setting up computer networks, consider hiring an IT or networking professional.

Then, you must decide whether each port will be a tagged member or an untagged member of the VLAN. If a port is an untagged member of a VLAN, the switch removes the existing Advanced remote support tools are used to fix issues on any of your devices.

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