Implementing Cisco IP Switched Networks (642-813 SWITCH) Tutorials
Basic Switch Configuration / LAB VLAN Trunk Setup pt. 2
Subtitles of the Movie (Implementing Cisco IP Switched Networks (642-813 SWITCH) / Basic Switch Configuration / LAB VLAN Trunk Setup pt. 2)
So we're continuing on with our discussion of VLANs set ups. The first thing we're going to do is get this VLAN Trunk between Core 1 and Core 2 running because we don't want our Access Switches to have to take the brunt of routing all of this Layer 2 traffic through them to get it from one side of the network to the other. Now there are a couple of ways to get this trunk up. Obviously all we have to do is set up one end of the trunk. We set one end of the trunk to Dynamic Desirable and we force one into the trunk to be a Trunk Port, then obviously the other end of the link being Dynamic Auto will pick up the fact that, hey this other end wants to be a trunk and so I'm going to be a trunk on my local end as well. However for our purposes, we don't want there to be any ambiguity to this configuration at all. We're going to set both ports that are between these two Core Switches to be Trunk Ports explicitly, that's all they can ever be. They can only be Trunk Ports, they're not ever going to be Access Ports, we're not even going to try anything else. And you'll notice once we set this up on Core 2, that the Trunk Port will come up on both Core 2 and Core 1. So the way we do this, we do Show CDP Neighbor just to make sure that we're going to configure the correct port. We're on Core 2 and we're looking at the Port 1 to Core 1 which is Fast Ethernet 023. So we'll go into Config T, Interface Fast Ethernet 0 slash 23 and we're going to do Switch Port and we're going to do Mode and there are the different modes we can set the Switch Port to, with regards to trunking. In this case, we're not going to do Private VLANs or anything like this, we're going to set it to Trunk Unconditionally. So Switch Port Mode Trunk, if I can type and we immediately get this error message and again this is a pretty common error message, that's why I forced it, just so you could see it. Basically it's saying you've not told me what kind of trunk I am going to use. I could be ISL, I could be .1Q, you've not specified what kind of trunk I'll be using. So until you do, you can't tell me to Trunk Unconditionally, I'm, I'm just going to try to figure it out on my own. So we're still on the Interface Configuration, so we just have to be issue a couple of commands before we can set this Trunk Unconditionally. So the first thing we'll do is we'll type Switch Port Trunk and right now we're looking for the Encapsulation. So we'll do Encapsulation and we have Negotiate, which is the default obviously. We have .1Q and ISL, since this is a newer switch it supports both .1Q and the ISL Trunking. In this case, we're going to force it to .1Q and now let's try that Switch Port Mode Trunk Command again. Hey look at that, it worked. So now it's going to tear down the physical interface and bring it back up as a Trunk Port. And if we exit out of Config Mode and now we do Show Switch Port, I'm sorry not Show Switch Port, it's Show Interface Trunk, we now see the Fast Ethernet 023 is 802.1Q Trunk with the other end of the Core Switch. If we go over here and we do the same thing, we do Show Interface Trunk, we now see that we're also trunking on Fast Ethernet 024 which goes over to the other Core Switch from this end. Now this is still on auto on this end because if you'll remember, since it's set to Dynamic Auto, once we told the other end, you're a Trunk Unconditionally, this end said well since you want to be a Trunk, then I'll be a Trunk too. So in this case, we'll need to change the configuration on Core 1 as well to force it to be a Trunk Unconditionally. So we'll do Show CDP Neighbor just to make sure we configure the correct port and it's Fast Ethernet 024 just as we would expect. So Config T, Interface Fast Ethernet 024. First we have to set the Switch Port Trunk Encapsulation to .1Q and then we can do Switch Port Mode Trunk. Of course, it will pull down the Switch Port and bring it back up as a Trunk that's been forced on both ends or actually since it's already a trunk, it won't pull it down. But if we do the Show Run Interface Fast Ethernet 024, we now see the Switch Port Trunk Encapsulation in the Switch Port Mode. If we do Show Interface Fast Ethernet 024 Switch Port, we now see that the Administrative Mode is Trunking Always, the Operational Mode is Trunking Always and it is set to .1Q Trunk. So now we've forced the Trunk between the two Core Switches in a production network and the best practices or at least the best practices I follow, would also to be force the trunk between the Access Switches and the Core Switches. We don't want that just for the sake of the lab, since it is set to to Dynamic Desirable on the Access Switch end. We know this Trunk will always come up between the Access and the Core because this happens to be rebooted. We will write the Config on both the Core 1 and the Core 2 Switch just to be on the safe side. And that has our VLAN Trunk set up. In the next video, we're going to set up VLANs and we'll also configure VTP to push these VLANs out to all of the switches. But for now that concludes our discussion of VLAN Trunking setup.
Tutorial Information
| Course: | Implementing Cisco IP Switched Networks (642-813 SWITCH) |
| Author: | Greg Dickinson |
| SKU: | 34304 |
| ISBN: | 978-1-61866-041-1 |
| Release Date: | 2012-04-20 |
| Duration: | 8.5 hrs / 102 lessons |
| Captions: | No |
| Compatibility: |
Vista/XP/2000, OS X, Linux QuickTime 7, Flash 8 |
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