Running out of IP addresses 2

[MattWray]

I would like to hear some feedback on what others have done when running out of IP's. We currently have your ususal 192.168 type network, class C. Problem is we are down to about 15 hosts at this site. My choices that I have thought of are to change the entire IP scheme and subnet, maybe a 10.10.x.x with a 255.255.0.0 network. Or to split the site into 2 networks and route between the 2.

Opinions, feedback or experiences would be very helpful, please...TIA!

Thanks,

Matt Wray
MCSE, MCSA, MCP, CCNA

http://www.sss-steel.com

 

[skotman]

Matt,
I'm assuming your talking about the 192.168.x.x private IP subnet. I dont know what kind of shop you work for so I may be WAY off. I'm going to use an ISP with DSL, Dialup, Office PCs and Servers for an example

Say your using 192.168.0.x for everything (REALLY small ISP)
and you have say 3 office machines, 15 DSL customers, and 100 dial up customers

That would work on all 1 class C but I would recomend netting it out for security reasons.

So say you grow, or plan to grow
Make your office subnet 192.168.0.x
DSL subnet 192.168.1.x
Dial up subnet 192.168.2.x
Servers 192.168.3.x

It seems like alot more admin work, and it is in the begining, but its ALOT easier to track down rogue or infected machines this way.

And since your already using 192.168.x.x it wont cost anything and you wont have to ASK anyone for more.

 

[MattWray]

Let me clarify a little.

We are a medium sized steel company with 6 offices. We are in a hub and spoke design. Each office is in its own subnet over Frame Relay back to us.

The office here has 2 buildings, approx 230 users split pretty evenly between the two. Right now this subnet is 192.168.77.x with a mask of 255.255.255.0.

Now the options that I'm thinking of are:

1. Route between the 2 buildings. Convert one building into say 192.168.78.x and add route statements between. My main concern with this, that I can think of at the moment is: getting a DHCP scope without adding another server on that subnet, and having it hand out the right IP's. (Thoughts on that, please)

2. Change the entire site to say a 10.10.x.x with a mask of 255.255.0.0.

Any experiences are still very welcome. Also, if anyone notices any flaws or things that could be better with either of my designs, please voice them. Could save me a lot of headache down the road...

Thanks,

Matt Wray
MCSE, MCSA, MCP, CCNA

http://www.sss-steel.com

 

[bierhunter]

Since you're using your own private addressing, you can play with the subnet mask all you want as long as you stay within the private range. You don't really need to completely re-subnet to a 10.x.x.x if you don't want to.

To keep from having to re-address your current users and at the same time add more address, here are some options.

192.168.76.0 /23 (255.255.254.0)
Usable Range = 192.168.76.1 to 192.168.77.254

192.168.76.0 /22 (255.255.253.0)
Usable Range = 192.168.76.1 to 192.168.79.254

You may have to make some minor changes, but you won't need to redo everything.

On a side note. If you do resubnet, here's something to think about if you have any remote vpn users. Many home routers use the 192.168.x.x networks. Although most vpn clients can be configured to avoid conflict with local and remote subnets, it's a good practice to avoid using the 192.168.x.x at the company. This way your corporate subnets won't have any conflicts with your vpn users' home subnets when routing traffic. The conflicts should be rare, but I like to avoid phone calls after hours.

Also, like Skotman mentioned, you may want to design some VLAN configs to help control broadcast traffic, security and such.

Good luck.

 

[MattWray]

Thanks bierhunter! That is exactly what I was looking for!

Thanks,

Matt Wray
MCSE, MCSA, MCP, CCNA

http://www.sss-steel.com

 

[bierhunter]

You're very welcome. Glad to help out.

I have to make a correction though with my post.

This: 192.168.76.0 /22 (255.255.253.0)

Should be: 192.168.76.0 /22 (255.255.252.0)

heh...that'll teach me to post before my morning coffee.

 

[ktmrandy]

What does the /22 mean after the ip address. I know what the rest of this stuff is but I have not seen the /22 before.

 

[bcastner]

255.255.252.0 (11111111.11111111.11111100.00000000) Binary

You can see that the subnet mask reserves 22 bits for the network address, and 10 bits to designate Hosts.

This is called CIDR "Classless InterDomain Routing", a way of avoiding all the waste of Classful schemes and to permit subnetting.

http://www.ralphb.net/IPSubnet/cidr.html

 

[ktmrandy]

Thanks for the clarification.

 

[bran2235]

VERY VERY SIMILAR Question...

Here at our HQs we are using 192.168.60.x /24 (255.255.255.0) network.

All of our branches that connect to us (frame) are using a similar:
102.x/24 = Branch 1
103.x/24 = Branch 2
104.x/24 = Branch 3
105 = Branch 4

Here's the issue:
Our HQs and another branch office are in the same physical building and both are on the same subnet:
192.168.60.x /24

I'd like to continue using the .60 network for our HQ and create a new subnet for the 'branch' w/in our HQ building..

How would I do this?
What do I need to aware of?
Any suggestions??
Would I need another router to route the new subnet?

TIA!!
Brandon