Need to learn about VLANs

Toggle sidebar Toggle sidebar
Mr Davo

Mr Davo

Distinguished
Feb 22, 2010
325
0
18,810
Hi Everyone,

I am interested in developing an understanding of VLANs. At my workplace I am running out of I.P. addresses and it has been proposed that the addition of one or more VLANs could alleviate the addressing issue. Ideally I would like to separate out client computers (desktops using Ethernet connections), printers, and Wi-Fi devices (laptops & smartphones primarily) onto separate VLANs.

I am particularly interested in how to communicate between the VLANs once they are setup. For example all client computers need to be able to access printers even though they will be on a separate VLAN.

Any links to tutorials, good books, or other resources will be greatly appreciated.

Kind Regards,

Davo
 
Sort by date Sort by votes
E

Emanuel Elmo

Reputable
Mar 21, 2014
232
0
4,710


I would suggest taking a cisco CCNA (200-210) course. This will cover everything you are asking. Get the certification and get setting up those switches.

Cheers!!!!
 
Upvote 0 Downvote
K

Kewlx25

Distinguished
Oct 23, 2009
2,275
0
20,160
You communicate between VLANs the same as your communicate between networks on difference switches, a router. VLANs are Network 101. They carve up a switch into separate broadcast domains.

Of course there are some got-chas, so make sure you understand how things work at the low level or you may have some really strange issues.
 
Upvote 0 Downvote
E

Emanuel Elmo

Reputable
Mar 21, 2014
232
0
4,710


that is not how subnets work. You can not just say that I have a /24 subnet and now lets make is a /20.

There are three classes of subnets and you can do what you want with them based on the class of subnets you have.

If you have a class C subnet than the most hosts you can put is 254

Which is why I suggested to the OP that he should take a CCNA 200-120. Basic configuration of routers, switches, servers and networking.

Cheers!!!!
 
Upvote 0 Downvote
jsmithepa

jsmithepa

Polypheme
Jun 14, 2014
13,096
263
60,840

Correct. If OP has a 192... then never mind, unless less than /24 is currently used.

However if OP had the foresight to use 10... or 172... to begin with and left enough "gaps" between active subnets, all it needs is to resize the mask. My old company used 10... and once I remember all I did was to shoot a general email out, EVERYBODY REBOOT WHEN YOU COME IN TOMORROW, and that night before the system went down for maintenance, I changed the DHCP mask. Easy-peasy.
 
Upvote 0 Downvote
B

bill001g

Titan
Aug 9, 2012
28,367
2,766
125,640
Of course you can just change the subnet mask and get more addresses. The concept of classes mean absolutely nothing and has not for many years.

Let say you are using 192.168.1.0/24 Why can I not just define 192.0.0.0/8 if I want to. Sure I may run into conflict on the internet but that has nothing to do with subnet masks.
 
Upvote 0 Downvote
E

Emanuel Elmo

Reputable
Mar 21, 2014
232
0
4,710


no you can not. I urge you to go back and refresh yourself on how subnet masks work.

Class C subnets only allow /24 to /30 address. Which is 254 hosts for /24 on a /30 you can have only 2 host for each subnet and that number of subnets you can have a /30 is 64

It isn't till a class A subnet that you can acutely have a /8. And of course this is all dealing with IPv4.
 
Upvote 0 Downvote
E

Emanuel Elmo

Reputable
Mar 21, 2014
232
0
4,710


http://www.subnet-calculator.com/

really... you can have a 192.0.0.0 /8. HMMM funny thing is check that subnet calculator. thing is that you have to select the class and that mask bits aka your / seems to only go from 24-30.

Once again it is not till you select Class A do you get you mask bits of 8. when you try to put in192.0.0.0 is physically does not let you because you can not have a 192.0.0.0 /8 WHY?

Because each class has a range and based on that range you can assign a subnet mask

Class A: 1.0.0.0 to 126.0.0.0
Class B: 128.0.0.0 to 191.255.0.0
Class C: 192.0.1.0 to 223.255.255.0

Now if you are talking about CIDR than that is a different because it only pertains to the scalability of the INTERNET and it was introduces to improve both address space utilization and routing scalability in the Internet. Which this has nothing to do with internal networks which the OP is referring to.

Internal network still refer to Class based ip address scheme. AS you have your own topology and your own ip address schemes, vlans, etc configured.

here is the best bit... this is directly from Cisco
Subnetting allows you to create multiple logical networks that exist within a single Class A, B, or C network.

I would also like to see that so called certification of yours.
 
Upvote 0 Downvote
B

bill001g

Titan
Aug 9, 2012
28,367
2,766
125,640
The whole concept of classes is outdated and has been for many years. Why don't you actually try to configure it and see if it works.

Maybe YOU should be the one to go back and take the CCNA class.

Why would you even think there is any difference between private network and public ones. The concept of classful networks when it was used had nothing at all to do with the private networks.

Do I actually have to post my CCIE number for a someone like you. I have had ccie for more than 10yrs in router and in security.
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom