Packet Tracer 4.2.7 - Configure Router-on-a-Stick Inter-VLAN Routing

hi everyone this video walks through completing packet tracer assignment 4.2.7 configuring router on a stick enter vlan routing this packet tracer assignment is a part of the switching routing and wireless essentials cisco version 7 networking academy curriculum so in this particular lab assignment we have two pcs on either side of a switch and that switch connected to one router now in module 3 prior to this module 4's assignment we learned how to create vlans we learned the difference between access mode and trunking mode and we learned how to separate our traffic uh but on a switch between different vlans so we want that so that those pcs to only talk to the same other pcs in the same vlan now there are certain situations where we do want to cross over to another vlan to talk to another computer so to be able to do that we have to involve a router to carry all of the vlan traffic and go across different vlans just like when we leave our router i want to go from one network to another one subnet to another we have to involve a router that router can help us travel from one vlan to another because technically they're on separate networks as well especially if you notice the networking scheme there pc one vlan 10 they're on the 172 1710 network dot zero network vlan 30 pc three over there is on the 172 17 30.0 network so they are on two separate networks as well so we must involve that router so this link here between r1 and s1 is going to have to carry both vlan 10 and vlan 30 traffic so you can imagine we're going to set that up as a trunk link here fa06 connected to pc 3 and switch one that's going to be an access mode link and it's only going to carry vlan 10 traffic the link here between vlan 10 and p or sorry between pc1 and s1 carrying vlan 10 traffic is also going to be a access mode link carrying only vlan 10 traffic so when traffic let's say we want to contact uh from pc1 to pc3 pc1 is the source pc3 is the destination the traffic is going to carry from pc1 to s1 it's only going to be vlan 10 traffic on that link it's going to go up to r1 it's going to contact our one sub interface so what we're going to do is we see we only have one link there we're going to kind of connect sub or create sorry and configure sub interfaces on g00 and r1 when it does that it kind of becomes the default gateway so there will be a g 0 slide 0.10 and there will be a g 0 size 0.30 so that one port can actually carry vlan traffic for both of the vlans and it becomes the default gateway for each one respectively now with that configuration in the traditional inter vlan routing we would have needed a separate port connected from switch 1 to r1 for every vlan that we have now we only have two so that wouldn't be too bad but if you've got 50 vlans in a medium to large size network or more that could get really troublesome because remember switches have a lot of ports on them routers do not so router's goals are just a route between different networks maximum you may have four or five connections probably to a router but usually that's it maybe six that's about it uh with the switch you usually have a lot more so you can imagine that you top out with the amount of vlan so that's why they came up with a router on a stick so that you only need one physical connection and you have a lot of sub interfaces so we'll see how to configure those in this lab so first we're going to review some commands from last module module 3 where we are creating vlan 10 and 30 on the switch it doesn't look like it really wants us to name it remember the naming is just for us uh you know as humans so to look at and name it but it don't matter it just looks at the uh number then it wants us to assign the access ports to the respective sides of s1 um and then make sure we've got that configured so let me zoom in here and then we'll get started so on switch one now i do recommend widening this window out in packet tracer uh we're gonna go do enable config t and to create vlan 10 we just do vlan 10 exit to create vlan 30 we do vlan 30 then type exit we don't need to name it you could but it's not necessary here um then we also want to assign the ports specifically so fa011 here is vlan 10 traffic to pc1 so i'm going to do interface fa011 so next we're going to put interface f8011 into access mode so with switch port mode access and then we're going to assign it to vlan 10 traffic with switchport access vlan 10. okay now the other side and you see it start negotiating there the other side is f806 carrying vlan 30 traffic with pc3 so we'll do interface f806 we're going to put it in access mode as well and we are going to assign it vlan 30 traffic we've got vlan 10 over here vlan 30 over there now these still won't be able to talk to each other even though there is a path that you could go from pc1 to switch one and then switch one to pc3 because they're on separate vlans we wanted that to happen in module 3 but now we want to be able to route them between each other involving this router now not only are these ports read but we need to configure sub interfaces here on g00 and that's the next thing our directions have you do is create those sub interfaces now there is a specific type of encapsulation that needs to happen which is 802.1 q um and that's just the name of the ieee standard so we're going to do is go to r1 here and again we don't need to do anything with the physical interface yet the book or the this lab has you actually configure the sub interfaces with an ip address and everything and then turn on the physical interface i say do it reverse if you turn on the physical interface first you don't have to go back and make sure that the sub interfaces are shut down because if you do it reverse if the physical interface is shut down the sub interfaces cannot come on and work so i'm actually going to do a reverse here and i'm actually going to go in and this is g00 that we're operating with on the router i'm going to go into g00 and i'm going to turn it on with no shut you don't need any physical configurations or anything like other than just turning it on you don't need any ip addresses or anything you notice here that we try to keep the naming scheme pretty simple so for vlan 10 we name it g 0 size 0 that's the physical interface but then we just put dot and then 10. we try to keep it simple so we're going to do interface g00 dot 10 for vlan 10 it's always dot whatever vlan number and then you see it changed to up if you had not turned on the physical interface it would not have come up automatically and then we'll do end cap i'm gonna shorten up encapsulation dot one q and then you need to put the vlan number this one's ten and then we'll put the ip address from our address and table you notice that this one and pc one are in the same subnet they're both on the 172.17.10.something network all right now we're going to do it for vlan 30 so it'll be interface g 0 size 0 still after the physical interface but this we're going to do dot 30 and you see it come up automatically we're going to do end endcap.1q that's the same but then we're going to do 30 for vlan 30 and then we'll do ipad and this one is 172.17.30.1.255.255.255.0. what happens is these sub interfaces become the default gateway for the pcs so we want to make sure that our pcs also have that information in there on s1 we also want to make sure that g01 is in trunking mode so we would go to interface g01 and we'll do switch port mode trunk all right because again it needs to be in trunking mode for this connection to work properly okay because remember trunk mode can carry multiple vlan traffic and that's g01 there we also in a real world situation here we want to make sure that pc one had the right configuration and we do here the default gateway you notice is that sub interface same thing for pc3 the default gateway is that sub interface so now we should be able to ping between pc1 and pc3 and we can go to command prompt here and we can try pinging a lot let's see if our default gateway works we get good reply so that is pc1 being able to go up or over to switch one and go up to r1 now let's see if we can ping 30.1 we get a good reply so that's the same physical interface but remember it is the other sub interface now let's see if we can go all the way to 30.10 and we get a good reply from pc1 all the way to pc3 and back and we also have 100 in our lab assignment

Channel: Anthony Lucas

Views: 2,924

Keywords:

Id: hBDLlEmGX_0

Length: 10min 27sec (627 seconds)

Published: Fri Feb 19 2021