Implementing Cisco IP Switched Networks (642-813 SWITCH) Tutorials
Switch and VLAN Basics / Network Models pt. 2
Subtitles of the Movie (Implementing Cisco IP Switched Networks (642-813 SWITCH) / Switch and VLAN Basics / Network Models pt. 2)
So let's continue on with our discussion of Network Models and we've talked about this new Campus Model that Cisco is moving towards. And with this new Campus Model there comes some recommendations with the arrangement of your VLANs and the arrangement of the overall networks topology that if you contact Cisco for any support or any consulting engagements they're going to push you towards this new model, even though, right now very few networks actually support these recommendations because again they're pretty new, in the last year or so. Now one of the biggest things that Cisco will push you towards in this new model and it makes a lot of sense when you think about their logic behind it, is that they want each of these blocks to contain all of the VLANs for that particular block. And it's kind of a stilted sentence, basically what I'm trying to say is, if you have VLAN 10, VLAN 10 needs to be all in this block and we don't need to have VLAN 10 here and then over here in the data center and then down here as well. Now I know there's a lot of engineers that will hear that and they say, well you know, that's just not possible in our environment. You know, we have wireless access throughout our entire footprint and that wireless access dumps into VLAN 478 and enterprise wide, that one VLAN is on all of our switches, everywhere. We can't, can't do that and you know, we understand that these networks aren't engineered that way and the logic behind their suggestion that you segregate your VLANs into each of these blocks is so that, from this point on, in your tree, it's all Layer 3. You're not depending on Spanning Tree here in your core and because you know, Spanning Tree if you have a Spanning Tree Re-convergence, you could have a network outage. And if you have a network outage here in your core, you're effecting more than just the people in this one block, you could be effecting everybody. You could be effecting access to the WAN or the data center or anything like that, so in this point higher in your architecture. They want to depend on Routing Protocols to determine the best path to get from for example, your Voice Over IP implementation into this data center. Because most Routing Protocols, especially if you use EIGRP and it's tuned properly you could have Sub Second Re-convergence times. EIGRP says hey this link has gone down, oh well I've got this feasible successor over here, I'm just going to start using it. And so traffic now goes, instead of going through this switch and then directly this way, it may not have to go through, over here and there, because maybe this switch failed. And EIGRP can figure that out a lot quicker than Spanning Tree can figure it out. The other big recommendation that Cisco gives you is to set up a Management VLAN which is a VLAN that is common to all of the switches in a block and that's where the Management Address is bound. So this way if someone's does happen to figure out your IP Addressing scheme, happens to figure out, hey this is my default gateway. Well, hey I'll bet you if I tune it into that Default Gateway, I'll get a login into the switch and then they can brute force the password. This way, you're Control Plane and your Data Plane are on separate addresses, to use kind of a switching term here and so you have added security because you can control access to that Management VLAN based upon Access Control Lists or based upon really anything. You could even make it where you have to initiate a VPN Connection to even connect to a server that connects you into that Management VLAN, if you wanted to really get secure and really get paranoid about it. And again this is a new Network Model and there's lots of documentation about how this Network Model came about and the logic behind it and how to best design your network to fit this model out on Cisco's website. And if you really want to dive deep into the Network Modeling, perhaps you're going for your CCDA Certification, god help you. Then I'd suggest you'd really go and look that up on Cisco's site, because other than the basic discussion of Cisco's new Network Model, all of that is really beyond the scope of the CCNP Switch course. And that concludes our discussion of Network Models.
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 |
VTC Sign up & Benefits
- Unlimited Access
- 81,350 Video Tutorials (14,200 free)
- Video Available as Flash or QuickTime
- Over 715 Courses
- $30 for One Month Access
- Multi-User Discounts Available
