• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 327
  • Last Modified:

Engineering a new LAN IP Structure

Hi All,

I am looking at redesigning our private LAN ip structure. We have 26 sites and the subnets are arranged as 192.168.0.0/24. We have from 192.168.0.X - 192.168.26.X subnets.

We have approx. 100 - 150 devices on each subnet. I was thinking of introducing a CLASS A network.

So 10.0.0.0/8. The reason? I can use the second octet as a SITE ID, Third Octet as a CATEGORY ID (eg, servers, wireless, laptops, printers etc etc) and the fourth octet is range 1 - 254 for the devices themselves.

Now I like this as a clear identifier of subnets, eg, a wireless device isnt working on 10.151.60.1/8, I know this is site Silicon Valley(151), Wireless Device (60).

However, I am concerned that CLASS A is too large for only 150 devices or so in each subnet, is it overkill? What are the downsides of this in a technical level? Should I pursue a CLASS B instead? I am assuming that over the next 3 years we will grow by double, in which CLASS C will not be a viable subnet range.
0
Network_Padawan
Asked:
Network_Padawan
2 Solutions
 
d3ath5tarCommented:
We split down by category, but not at the level you are talking.. At the subnet mask you are talking the subnets would be huge...

How about this?

10.Global Region.SiteVlans.Device?

So for example;

Split world or country into 8 chunks (a /11 mask) - regions a-h or whatever you want to call them

So sites in Region A would exist between 10.0.0.0 and 10.31.255.255, B would be in 10.32.0.0 to 10.63.255.25

each site would become a /21 mask which would give you 8 .24 vlans on the site

So site A in region A would 10.0.0.0 to 10.7.255.255

Within Site A you would have your 8 /224 vlans for your device types

Helps?


0
 
JermTheWormCommented:
I don't see any issue with this idea at all, they are after all just numbers available to use for whatever you need.
0
 
Network_PadawanAuthor Commented:
Well someone said that I shouldn't do it with class A because if I need to VLAN a segment, I need to use an entire different IP scheme, either 172.16.x.x or 192.168.x.x.

Also, he was concerned that Class A would permit more chatter on the network, though what difference does CLASS A and B have to do with chatter if there are only 150 or so devices on the subnet anyways.

I mean, you need to reach approx. 500 devices before you think of segmenting right?
0
Improve Your Query Performance Tuning

In this FREE six-day email course, you'll learn from Janis Griffin, Database Performance Evangelist. She'll teach 12 steps that you can use to optimize your queries as much as possible and see measurable results in your work. Get started today!

 
d3ath5tarCommented:
You can use a classless 10 network. You define it by the method I described (which I use globally!). If you define each site using 10..x.x.x/8 then you essentially putting each site on the same subnet. You don't want that. You can use a 10 network but using smaller subnets (classless).

Also, by using the method I have given, each vlan is a /24 subnet so you are defining your broadcast boundaries as 254 devices..... I would never recommend anyone have a subnet containin 500 devices... your broadcast chatter would get redonkulous.....

Cheers
0
 
pergrCommented:
If you assume that you are routing traffic between sites, you cannot have the networks in each site overlapping each other. That means that you, at least, need to divide up the 10/8 to 26 different subnets, to start with.

If you use 10/13 networks, you can have 32 of those, so if you never expect more than 32 sites that is enough, otherwise use /14 - or larger mask.

You foresee up to around 300 devices per site, which means the smallest subnet mask you want is /23, which give you about 500 addresses per subnet.

So, effectively you need to choose a subnet mask between /14 and /23 - these is not really any way around that.

Now, it will probably make sense to choose a subnet mask that is easy to work with, and that is /16 that goes right between octets.

You now have networks like:

10.X/16

Possibly written like

10.X.Y.Z/16

X will identify the site (and each site will have a unique subnet)
Y will identify the device type
Z will identify each device

Y and Z will all be on the same subnet within each site.

You can have 65000 usable addresses in each site.
You can have 254 usable addresses for each device type, in each site.
Of course, you can have Y=1 and Y=2 for PCs, giving 500 addresses for PCs.
You can have 256 different sites.

So, concluding, your own idea was great, but you just needed a different subnet mask, the /16.

Only if you are not routing, can you use the /8.
0
 
Network_PadawanAuthor Commented:
Thanks. Obviously I need to use /16. Not sure why I thought /8 was the best solution, its obviously not.

Thanks guys.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Cloud Class® Course: SQL Server Core 2016

This course will introduce you to SQL Server Core 2016, as well as teach you about SSMS, data tools, installation, server configuration, using Management Studio, and writing and executing queries.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now