Need some advice on learning networking

[BillyCarpenter]

Re: Need some advice on learning networking

I've continued to learn more about wireless technology. Specifically I was interested in WAP's (Wireless Access Point) and WAC's (wireless access controller).


There was one specific video (I'll post below) and the guy was talking about "tuning" a WAP and the potential pitfalls when configuring these devices. As I'm listening to the video, I was reminded of what rthonpm had told me in this thread.

I won't drag this post out but, personally, I'm a huge rthonpm fan.

[BillyCarpenter]

Re: Need some advice on learning networking

Just to follow up on Wireless Access Points and Wireless Access Controllers....


There are 2 ways to configure wireless. You can use standalone access points or we can use wireless access points with a wireless access controller.


Let's first talk about a standalone access point...also known as an autonomous access point. I have a couple of Aruba (Hewlett-Packard) access points at my office. Here's the way that works.

I plug one of the Aruba access points into my switch, give it an SSID name and it pulls a DHCP address. Side note: This becomes my Master Access Point. When I plug in the next access point, it picks up the wireless signal from the master access point and receives it's configuration. In other words, it has the same SSID, authentication and you'll be able to roam between the 2 access points.


If you stayed with this post, stay with it a little longer. It gets more interesting.


The problem with the autonomous setup is that the Access Points must be at the proper distance and most often the signal strength must be adjusted up or down so that there's not too much overlap. This is undesirable and a wireless device won't roam properly. Imagine that you have 30 access points and you must tune all of 'em? This would work if you only have a few but you get the point??!!


Enter the Wireless Access Controller. It is my understanding that, at least with Cisco, the controller manages all the Access Points. It automatically tunes signal strength, channel and everything else.

I still need to verify this for myself, so I think I'm gonna purchase some used Cisco gear and give it a try.

[BillyCarpenter]

Re: Need some advice on learning networking

I continue to go through the section on wireless in my CCNA course and it has gotten really deep and complex. They are now talking about wireless in a production network and it's a whole new ball game where wireless is concerned. So many things to consider in a production network but there's a solution for all of it, we just have to learn it. And learn it we will.


I don't know where the best place to start so lets start with the Wireless Access Controller.


In every production network, you're likely to see a Wireless Access Controller. I'm not gonna cover everything, but it's important to understand that most of the data from all the individual access points passes thru the controller FIRST and then gets sent to the switch and from there it gets sent to the intended destination. Because of this, the switch must be configured properly for the Wireless Access Controller. That means an ETHER-CHANNEL must be configured on the switch to allow more bandwidth for the Wireless Access Controller.

Also, trunk ports must be configured to allow VLAN traffic from the switch to the controller.

One other thing is that WPA personal uses pre-shared keys and that will work at home but not on a production network. If an employee quits, we'd have to change the password and then notify everyone of the new password. That's unmanageable.

WPA Enterprise uses a AAA server and individual usernames and passwords are created for each user to log on the wireless network. If an employee quits, we simply delete that user and he no longer has wireless access.

[BillyCarpenter]

Re: Need some advice on learning networking

Just to follow up on Wireless Access Points and Wireless Access Controllers....


There are 2 ways to configure wireless. You can use standalone access points or we can use wireless access points with a wireless access controller.


Let's first talk about a standalone access point...also known as an autonomous access point. I have a couple of Aruba (Hewlett-Packard) access points at my office. Here's the way that works.

I plug one of the Aruba access points into my switch, give it an SSID name and it pulls a DHCP address. Side note: This becomes my Master Access Point. When I plug in the next access point, it picks up the wireless signal from the master access point and receives it's configuration. In other words, it has the same SSID, authentication and you'll be able to roam between the 2 access points.


If you stayed with this post, stay with it a little longer. It gets more interesting.


The problem with the autonomous setup is that the Access Points must be at the proper distance and most often the signal strength must be adjusted up or down so that there's not too much overlap. This is undesirable and a wireless device won't roam properly. Imagine that you have 30 access points and you must tune all of 'em? This would work if you only have a few but you get the point??!!


Enter the Wireless Access Controller. It is my understanding that, at least with Cisco, the controller manages all the Access Points. It automatically tunes signal strength, channel and everything else.

I still need to verify this for myself, so I think I'm gonna purchase some used Cisco gear and give it a try.

When I said I'm gonna purchase some used gear and give it a try, I mean in a lab environment.not at the school.

[BillyCarpenter]

Re: Need some advice on learning networking

Each new technology that I learn usually starts and ends the same way. At first I don't know much about it. Then I learn the basics. Then I get into learning how to set it up in a production network. In the end, I'm always amazed that someone figured out how to make it work.


In my opinion, going with a Wireless Access Controller is the way to go. But it will depend largely on how many WAP's you'll be using and budget.


I've also learned which software to use to measure the strength of the wireless signal (and other info) and that will help in determining where to place the wireless access points. But again, like rthonpm said, there are other factors to consider and experience will come in handy.


I really want to talk about setting up wireless controller in a production network but we'd have to do a deep dive and I think it would largely be a waste of everyone's time. It is interesting, though.

[BillyCarpenter]

Re: Need some advice on learning networking

I bit the bullet and ordered the following off Ebay:


-Cisco 3750x (Layer 3) switch with 48 ports and dual power supplies that supply up to 30 watts of power per port.

- Cisco WLC-2504 (Wireless Lan Controller)

- (5) Cisco 3702i (Wireless Access Point)


It's a bit of an overkill on the switch but it will come in handy in the future.

I believe with a little practice that I can get this down.

[rthonpm]

Re: Need some advice on learning networking

I bit the bullet and ordered the following off Ebay:


-Cisco 3750x switch with 48 ports and dual power supplies that supply up 30 watts of power per port.

- Cisco WLC-2504 (Wireless Lan Controller)

- (5) Cisco 3702i (Wireless Access Point)


It's a bit of an overkill on the switch but it will come in handy in the future.

I believe with a little practice that I can get this down.

Good equipment for learning in a controlled environment, but keep in mind if you look to use second hand equipment for future jobs to check the end of life dates for them. The 3750X went EOL in 2019 so if there are any vulnerabilities found for it since then, they won't be patched.

The biggest shift from the MFP world is getting the lifecycle management right.

Sent from my BlackBerry using Tapatalk

[BillyCarpenter]

Re: Need some advice on learning networking

Good equipment for learning in a controlled environment, but keep in mind if you look to use second hand equipment for future jobs to check the end of life dates for them. The 3750X went EOL in 2019 so if there are any vulnerabilities found for it since then, they won't be patched.

The biggest shift from the MFP world is getting the lifecycle management right.

Sent from my BlackBerry using Tapatalk

That's the kind of stuff that I need to be reminded of because I'm focusing on learning the technology and forget about that. Thanks.

[BillyCarpenter]

Re: Need some advice on learning networking

As I said previously, wireless is a different animal when it comes to a corporate network. You have to ask yourself this question: what if a building has one wireless network and hundreds of users in the same building? What would happen if hundreds of users logged on in the same VLAN?

Answer: The same thing that would happen in a wired network -- a potential broadcast storm.


We know from our training that VLAN's break up broadcast traffic and as an added benefit, it adds a extra layer of security

Here's how this works:

The WAP's add the vlan tag to the frame which is then sent to the switch. So that means that we have to create the vlan's on the switch and associate them with the correct ports. That's easy enough.

However, how do we get load balancing between the different VLAN's? That's the goal. We don't want all of the wireless traffic on 1 vlan. We want to load balance over the different Vlans that we have configured. But how?


More on that in a minute.....

[BillyCarpenter]

Re: Need some advice on learning networking

Okay, so the $64k question is, how do we spread out some of the wireless network traffic between the different VLAN's?

This is a quite lengthy process. We need to go back to the basics? What is needed to route traffic between VLAN's? Answer: a router. That's the reason I ordered a Layer 3 switch.


But that's not all that we need to do. On the Wireless LAN Controller we have something known as Interfaces and Interface Groups.

I'll try to explain to where it makes sense.

When we create an interface, it is associated with a VLAN. Once we create multiple interfaces, we then add them all to a group and after a little configuring on the Wireless Controller, it will load balance between the different interfaces/VLANs.

And there you have it.

[Will541]

Re: Need some advice on learning networking

I guess I'm posting this in the right forum.

Until about a year ago I knew NOTHING about networking. Now I know enough to get the copiers networked and I can set up scan to PC and email. But I have ran into a range of problems @ the customer's office and had to call someone else to solve the problem.

I haven't had much time to devote to networking because I've been busy learning other stuff. I think I'm ready to tackle to world of networking.

How did you guys get your training and are you satisfied with your abilities?

Are there any books or videos that you recommend? I'm open to any suggestions. Thank you.

https://www.educative.io/paths

I like it because the Learning Paths are carefully curated to help you achieve a specific learning goal and there is a free trial.

[BillyCarpenter]

Re: Need some advice on learning networking

I've been prepping for when the Cisco gear arrives so that I'll be as far along as possible on setting up the WLC. Immediately I ran into a challenge.

The WLC relies heavily on DHCP to communicate with all of the WAP's and I need to use the DHCP server from the Cisco switch because it has options that you won't find elsewhere.


Anyway, currently I'm using the ISP router for DHCP and there's no way of turning it off. The only solution I could think of was to put a router between the ISP router and the network. We know from our training that DHCP uses a broadcast signal and a broadcast can't go past a router. Thus, I will be able to use DHCP from my Cisco switch without worrying about the DHCP from my ISP router.


This all sounded great in theory and in the end it worked beautifully but it was much more work than I anticipated. I had to set a default route and do a lot of other things to get out to the internet.

Right now I'm using the DHCP server on my Server 2019 and that's the first time I've ever set that up. Baby steps.

[BillyCarpenter]

Re: Need some advice on learning networking

I need to make a correction. I said that Cisco WAP's rely on DHCP to discover the WLC and that I must use a Cisco DHCP Server because it has DHCP options that aren't available elsewhere. Upon doing more research, it appears that other devices do support those options.

The option that I speak of is DHCP Option 43.

I found this is Cisco's literature.

Introduction


This document describes how to use DHCP Option 43 and provides sample configurations for DHCP Option 43 for lightweight Cisco Aironet access points (LAPs) for these DHCP servers:


Microsoft Windows 2008 Enterprise DHCP Server





Linux Internet Systems Consortium (ISC) DHCP Server


Cisco Network Registrar DHCP Server


Lucent QIP DHCP Server


When a Cisco Wireless Unified architecture is deployed, the LAPs can use a vendor-specific DHCP Option 43 to join specific Wireless LAN Controllers (WLCs) when the WLC is in a different subnet than the LAP. Refer to Wireless LAN Controller and Lightweight Access Point Basic Configuration Example and Lightweight AP (LAP) Registration to a Wireless LAN Controller (WLC) for information on how to configure an access point (AP) to join a WLC.

[BillyCarpenter]

Re: Need some advice on learning networking

..

Microsoft DHCP Server


This section describes the configurations necessary on the Microsoft DHCP server in order to use DHCP Option 43 for WLAN Controller discovery.


Cisco 1000 Series APs
This section describes how a Windows 2008 DHCP server is configured in order to return vendor specific information to Cisco 1000 APs. You need to know this key information:


Vendor Class Identifier (VCI)


Option 43 sub-option code


Management IP address(es) of WLAN controller(s)


The VCI for a Cisco 1000 Series AP is always Airespace.AP1200. As stated, the Option 43 sub-option code for the Cisco 1000 Series APs is type 102 (0x66).


Create a new vendor class in order to program the DHCP server to recognize the VCI Airespace.AP1200. In the Server Manager window, right-click the IPv4 icon, and choose Define Vendor Classes.

DHCP OPTION 43 for Lightweight Cisco Aironet Access Points Configuration Example - Cisco

[BillyCarpenter]

Re: Need some advice on learning networking

I'm finding wireless controllers and access points endlessly fascinating. It's a huge amount of information to learn but it's fascinating.

For instance: DHCP Option 43 must be used but only if the Access Points are in different subnets. If they're in the same subnet then they can be found via broadcast signal.


EDIT: In the lab that I'll be conducting, I'll use several VLAN's so that means different subnets.