Midsize Office Architecture! Ep.3: Real-World Business Switch Network Build

our office is growing we're moving beyond a single building location with one network closet into multiple rooms and multiple buildings by time we're done here you will be able to design switch connections for a highly available mid-sized office environment I'm so excited because it's time to grow beyond a small office environment see up till now we've had all of our perspective in what I'm calling suite for the office that we actually built an entire cabling series around we moved in we wired new ports we installed switches and even in the last nugget we talked about connecting those switches together two switches in the same rack going beyond just using a single connection and talking about the impact of spanning tree and link aggregation ports and the consequences of using an unmanaged switch and now it's time to expose the rest of the story suite 4 is actually an expansion suite of the main office of the company that we're working with and now I want to take you over to suite 1 which is actually the larger office and begin getting you in the mindset of graduating beyond our small network design into planning to build a midsize network environment well this is the office that we know and love we built this in the cabling series installed the rag did all the cabling install the switches and got this office connected but now it's time to go into the great beyond come with me walk into this area which is the shirt company and down the hallway and out the front door and when I showed you the map of the office suites I had a couple that are question marks that wasn't door prizes those are just tenants that I have no idea who they are so we're gonna walk right on by them into that suite one down at the end and here we are turn on a few of the lights there we go and let's come into the what I would call the MDF of this organization and close the door looking up there we've got some work to do so this was the one that was originally powering this company and if I look right here I see there's a battery backup sitting in the rack there's a little server going right here looks like a DSL modem shoved right here there's a cable modem mounted on the wall over there so a couple internet connections coming in I see switches routers and just a big ol cabling mess now if I stand on the chair here because this thing is not within arm's reach I can see that there's actually a router sitting right here as well as one two different switches and patch panels galore so this office is actually connected to the other office with right now two ethernet cables that are running across the ceiling through the rafters over the other two mystery companies and down into that expansion suite now the irony is even though that other office space has a larger room I would consider this the MDF and the reason why is because this is where the router actually lives as well as where the internet connections come in and where most of the connections are terminating now we couldn't make the other office suite the MDF because it is just a label but at a gut level I would say that would require us to move all the internet connections over there which would be a cost because we'd have to have all the carriers come out and move all the cable modems and DSL modems and everything else feeding this organization and if nothing more suite one just has a feel of the MDF its central if this business grows beyond that second suite into other Suites of this office complex this would be the central hub where everything would come back and connect to so now here's the dilemma I'm looking here and we've got two switches that are connecting this office and connections that are running over there this is beyond just connecting two switches together with redundant connections how should we connect these two switches to those two switches well you could just start daisy chaining those switches together which is what I call a model of non design take the two switches in suite 1 connect them together we've run a line over to suite 4 down there connect those together with one cable and now you have this long chain of switches which in the end leaves your network typically looking like this because you're just plugging things together to make it work and work it does as a matter of fact if you have unmanaged switches meaning switches that don't support spanning tree you have to go with the design like this because if you implement any kind of redundancy a line like that or a line back like that or you know running two lines over between the two offices you cause a loop in the system since there is no spanning tree there is no lag in the unmanaged world or you can get managed switches and go with an intentional design the first intentional design for switch port connections is known as a single core design this is where you elect one switch to be considered your core and all the other switches connect there it's like the old saying all roads lead to Rome in this case all of our roads lead back to the core now I want to make sure that I'm bridging the logical view which is what's shown in this picture with what is physically happening in the building with the MDF and the IDF so I'd like to ask you the question if you were to physically map this out in your mind where do you think the MDF and the IDF would be of this building pause the video if you need to think about it I would suggest that this would be the MDF and these switches down here would be in the IDF now depending on the building it might be two different IDF's IDF one on the Left IDF two on the right or in the case of the office that we're working with right now both of these switches could be in the same IDF now remember the MDF and the IDF are just locations their names that we assign to places in our building that means something to us my youngest son's name is Nehemiah but I call him me oh I do that because it's easier to say and I love the movie The Matrix he is the one so I've assigned some value to that name but I could call my son Frank he'd be confused for a while but he'd get used to it if the label Frank has some value to me some deep meaning then I'd do it so usually the MDF is the room that holds most of your servers it's the room where the internet connection usually comes in it's usually the room most central to your facility in the case of the building that we're working with the MDF will be that messy room that I just showed you now that's not the biggest room but it's the most central room and it's where all the internet activity comes into place so that will be where we design our course which now I want you to see something here look at the connections coming from the course which to these secondary switches by the way in the industry they usually call these access switches just think of it as that's where things access the network I chose to connect them with two cables and I'd have the question for you how do you think spanning tree protocol plays in all of this if we left everything at default which means spanning tree is normally on what's going to happen well I'll tell you what will happen spanning tree we'll look at this network and realize that a loop is possible remember if a single broadcast comes out and goes down this line that broadcast is going to loop back around and back around and back around so spanning tree will step in and disable one of those connections it's gonna do the same exact thing on the other side over here it's gonna see a loop potential there and disable one of those connections so do you think that there would be a benefit to us and using link aggregation at all absolutely I would take these and bundle them into two aggregated links now make sure that you follow link aggregation doesn't allow you to bundle all of those connections into one big link this is only between directly connected switches so I could make two bundles of two one here and one here that way spanning tree doesn't have to come in and disable one of those links and I actually can use more bandwidth between those switches do you understand why that management is so critical these types of things have to be configured they don't just happen now I want to bring this back around because I have a superpower where I can feel the questions going through your head you're going okay I get it now we've got the MB up how does this relate to what we just saw in the actual office I mean there was two switches in the MDF right so where does that second floating switch go that's out there that's a great question and I'll even chase that with a question of my own what happens if this course which goes down yeah that's really bad everything else is gonna go with it because you lose that core these guys are now little severed limbs they can't reach the internet business stops and that's why the single core design is only for the smallest of networks we've got a single point of failure and that's not good for that we want to move to a dual core design oh yeah that's awesome so where's the MDF and where's the IDF you feel it right now right MDF right there that's our two switches notice they're tied together resilient ly redundant ly we have these guys that are sitting in the IDF so to tie this back to our physical network that I walked with you a moment ago this is suite one this is Suite 4 look at what we've done we've got those two switches that we have in the MDF cabled redundantly they're not only connected together with redundant links which would make a great lag between those two switches but look at the cabling that we can run over to our suite four we've got our suite switches right here connected to the two cores so let's let's play out the scenario chunk fling get some play I was thinking back to the tour that we did at the beginning did anybody else see this and go what is that seriously that's terrifying for a network environment I'm assuming we've got internet connections plugged in their switches plugged in there maybe that's the fire alarm I don't know but it surely isn't good we're gonna need to do some power rerouting it as part of this project but like I was saying before and that current design it surely isn't going to take very much for one of those switches to go down but look at what happens this connection fails this one comes up and we're routing out to the internet just as if nothing happened yes we do lose some devices if we have devices plugged into that switch and they don't have a connection elsewhere that's Sally's computer that's the wireless access point powering half of the building you're gonna lose some stuff but the business as a whole stays online now you might be thinking to yourself okay well what size of business do I have to reach before I can justify going from a single core to a dual core and that is a great question but it's not quite the right question the size of business doesn't necessarily matter it's what does failure cost you you might have a one or two person company and maybe you've come up with a brilliant website and if that website were to go down for an hour you would lose half of your clients that's a pretty high cost of failure you can also have a fifty person company where most of people are outside digging holes because you have a hole digging company if the network goes down you know that's alright it will come back up hey Harvey stop surfing the web go out and dig a hole you see what I mean you have to think about what is the cost of all employees not working because their computers stop functioning what is the cost of missed customer opportunity because the customers couldn't get to your website or your people couldn't call out or your phone system went down because it ran on voice over IP what is the cost of losing existing customers because you can't service their needs and all the other overhead that runs your company that you still have to pay but your business has stopped functioning because the network is down these are some examples of hard cost calculations and I'll tell you for most companies it doesn't take too long before you say you know what I think I'm gonna throw another $1000 switch in there because one hour of downtime would cost us probably triple that or whatever your business model is now keep in mind I'm talking hard cost here but there's something that happens to employee morale when that spreadsheet they were working on is lost and they have to redo it or they were in the middle of closing a deal in the screen-sharing stopped those are things you can't quite put a hard cost around but they do have impact now I don't want to leave this dual core design picture without answering these questions how does spanning-tree play in this well remember I said previously that one of the switches in your network will be elected as the root bridge you do that with the configuration when you get into the switches and I'll show you how to do that later on a whole other switches see that and immediately bow down oh hell the root bridge you are the almighty center of the network and so they find the best way to get to that root bridge and that's the one that they uses their primary connection this guy is like hey I only have to cross one link right here and I get to the root bridge this guy's like well hey I only have to cross one link to get here and I get to the root bridge that's that's great these links I actually have to go through another switch so I'm going to block those and spanning-tree has done its job now Lag does not play in this part this situation because those are connections that go between switches I can't bundle a connection going from say switch 1 and switch 2 to switch 3 I can only bundle connections like this and like this connections between the same switches so the lag can play in right here and since these two switches are sitting right next to each other in a wiring closet I just use these little 3-inch cables to connect them together I don't need to run any long strands across the ceiling right this is so good I'm loving this conversation now I know some of you are looking up here at these internet routers and going well okay does spanning-tree play here bite those fingernails spanning-tree does not actually play up here because those are not switches and what's the name of this series our eyes are all focused on the switch design we'll get into the internet routing design later on i promised at the beginning of this nugget that you will be able to design switch connections for a highly available mid-sized office environment I'd love to run through one final scenario with you the elementary school a new elementary school has just moved into a vacant building that be this one they've run approximately 180 cables from various areas of the school to the rack of equipment in the boiler room I'll show you a floor plan in just a second they plan to move into the adjacent vacant building over there which has a mirrored floor plan as the school grows the school has hired you to install and configure switches for their facility determine the number of switches required for the existing building and the model that they should follow for the new building so here is the floor plan of the elementary school you can see the various classrooms down there at the bottom nurses office teachers lounge so a hundred eighty some cables have been run from all of these locations right here to the center of the boiler room right here on the east wall of the building it will be the second building that they'll move into that has a mirrored floor plan to this this is what we need to design well here we are on a blank slate right here I want you to pause the video and on a piece of paper design this one yourself then come back and I'll show you how I designed it did you pause it hopefully you did so here's some thoughts in this series and actually the previous cabling series on now I've only introduced you to 24 port and 48 port switches that's what those circles are supposed to represent there's 24 individual dots on there and there's 48 individual dots right there those are known as stackable switches they are always almost 1u in size and you will see them all over the place in network environments I'm going to do my initial design using that equipment because that's what I would have expected you to do so here's my thought in the middle of that campus is the boiler room we would probably have a two-post rack and the first thing that I would do is install 248 port switches that I would designate as the core switches well call them switch 1 and switch 2 I would mark one of those as the spanning tree root bridge that means it's the king of the network all the switches try to find the best way to get to that root bridge and we haven't gone into too much stuff with spanning tree as of yet but you'll find when we do you can also set up AB spanning tree backup root we'll call that the queen of the network when you set up resilience and redundant connections throughout your campus all the switches will try to get to the king of the network and block any redundant links they have to make sure a loop doesn't occur but if that's which were to fail I'd want them to recalculate all their best paths around the network to go to the backup route or we'll call it the Queen now we're not going to get it into it in this series but this is where you would typically attached your redundant routers that get you off to the internet more on that later so quickly with a rough sketch of about how many ports they have which was a hundred eighty ports I'll pull out my calculator and do 180 divided by 48 that gives us 3.75 so we need at a bare minimum for 48 port switches to be able to service all a hundred eighty cables run into that room and just out of curiosity I'm going to take 48 ports times 0.25 which is our left over so that gives us 12 ports of flexibility so if we sliced in two more switches will just call it switch three and switch 4 and cabled all hundred eighty cables right into those switches we would have 12 ports left over now that may be ok but I'm thinking that's just the cables that feed all the building you have those internet routers that are sitting in here you probably have some servers that are either sitting inside of that rack or somewhere in this room that need to plug in there and they'll need redundant connections as well what I'm trying to say is 12 ports really isn't that much left for overflow personally when I look at the cables and I see a hundred 80 cables I want to add a 20% extra buffer for the stuff that nobody really thinks about the UPS power supply management the alarm system sitting in the room the other lines that I would draw on this rack that I really can't think of things for right now stuff that all plugs into these switches that you just didn't think of so if I were to take those 180 cables and do a 20% increase that gives me 216 ports that's 36 extra totally justifies adding a fifth switch to that rack switch number five junk now how are these connected great question with the two core switches I would time together with to at least individual cables that I would splice together in a lag switch three would connect one interface to switch one one interface to switch to switch for the same switch five the same switch six not pictured here the same obviously I'm getting a little bit messy in my drawing but you get the point for all the devices that are plugged in here that gives them at least a plus one redundancy if our core switch goes down they can go through switch number two which now has the ability to reach the internet routers and we would often take our servers and split their interfaces between the two if we have essential devices that need to be accessed all the time this is good and that works but what about when we introduce the second building we just put the network design in play for the main building where we've got that rack with the five switches sitting in there now 180 some cables all feeding that room but the scenario said that the school is planning to move into the adjacent building that has a mirrored floor plan so in that building over there to the right of this one I would expect the same kind of design we've got the rack we've got the five switches we got the 180 cables running into there but then how do you connect that rack and building one over to the rack and building two exactly like this course which one to course which one course which one to course which to course which to to course which one and course which two to course which two and remember inside of each building as I said before each of these switches has redundant connections to course which one and course which to that and like that same thing over here mmm-hmm mmm-hmm and it's getting a little bit messy and do you see why I put that 20% buffer into our hundred eighty cable calculation one hundred eighty cables didn't even include all of these up links I also want to make sure that you catch that design it's what's needed not just between buildings but also between MDF and IDF in the same building our scenario assume that all hundred eighty cables of this building wired to that single boiler room and that we followed that mirror design over here in building two but most of the time in a building of this size you'll reach a point that running cable from all the way over there in the teachers lounge to the center boiler room becomes too far so rather than running all of this cable from far locations you'll choose another room as the IDF get that principle out of there this school doesn't need one his office should be the IDF and you'll install a smaller rack of equipment in here just a wire we'll say the west side of the building then this IDF over here who's ever heard of a refrigerator room IDF brother and that IDF would handle all the wiring for this side of the building you're gonna need to connect those racks of equipment back into the MDF and it uses that same design model let's say each IDF only had two switches in it top switch to course which one bottom switch to course which one top switch to course switch to bottom switch to course which to do you see the model and do you see why I wanted to do this scenario with you oh man this is negatives gone a little bit long but hasn't it been good it's not just us it's delicious all of this design and concept of how these switches should be wired together a model to expand beyond just a single MDF and a couple switches all the way out to multiple [Music]

Channel: Viatto

Views: 9,898

Keywords: network install, network switch, Jeremy Cioara, Business switch network, real world install, switch install, patch panel install, real world, installation, Real world install, cable management, fiber cabling, Fiber Cable, CCNA, fiber, fiber types, information technology (industry), information technology, it, tech, networking, it jobs, it fundamentals, how to, learn IT, networking tutorial for beginners, home network, Keeping IT Simple

Id: FvFoyFuegzA

Length: 22min 8sec (1328 seconds)

Published: Wed Jul 08 2020