Discussion on:

Create a superscope to solve the problem of dwindling IP addresses

Have you come up against the problem of insufficient IP addresses? What solutions have you considered?

While it does allow you to have more IPs and thus more clients into the network. You are now expanding the size of your broadcast domain, so depending on the applications you run in your network it may or may not be ok to do so. I read somewhere that 20% broadcast rate is as high as it should go so if you look at your broadcast rate and its nearing this number then getting another interface in your router and VLANing your switch might be a better way to go and you dont even have to get another DHCP server just use IP Helper address (or equivalent) and create another scope on your server.

You're essentially running 2 subnetting schemes on a single physical network segment. All traffic between the subnets have to ride a single interface to the router before it can return over the same interface to get back to the network. It does have the advantage of limiting the broadcast domain though.

I had to do this recently due to limited network ports near some networking equipment. Periodically, the Linksys router would bug out and start flooding the network, shutting down all LAN & WAN traffic. I do not recommend putting two logical networks on the same physical network unless you have a really, REALLY good reason to do so. NICs are cheap, downtime is not.

J.Ja

This seem to be a very complicated solution for such a
simple problem.
First. Shame on you if you are connecting all your users to
the internet with internet routable addresses; they should
be behind a firewall or router capable of using PAT. ALL
users should have private address space.
If you need more that 254 address on a single physical
network; use subnet masking.
Example - The pool address of 192.168.0.0 /22 will
provide 506 or so addresses. Move that mask to /22 and
you have over a thousand addresses. Not that I would ever
recommend putting a thousand users on a single
unrouted segment.... but you could!
Did I miss something on the original questaion?

I agree, resubnetting is the recommended solution from Microsoft:

http://support.microsoft.com/?kbid=255999

All you have to do is set your subnetmask.

However, its 192.168.0.0/23 (subnetmask: 255.255.254.0) that provides 510 available addresses. 256*2-2 = 510

192.168.0.0/22 (255.255.252.0) gives you 1022 available addresses: 256*4-2 = 1022

I'd suggest you consider VLAN's

if your block of ipv4 addresses isn't large enough to meet your needs, then switch to ipv6, where there are enough ip addresses for every electronic device we currently have made, and will make for the next 150 years to have one permanent ip address.

a complete non issue.

Not if you are still on NT4, or perhaps using XP-Home edition.

They do not support IPV6

he-he-he As my students discovered! - part of teh learning process.

of the software vendor.

all operating systems worth using will default to ipv6.
[which lets ms stuff out of the running, ms hates ipv6 ]

Vista ships with ipv6 installed and running by default.

The main problem I think most small businesses will have with ipv6 is that a large amount of the infrastructure out there (routers and switches) don't support ipv6. Most people need internet access, if their router doesn't understand ipv6 and they're out of ipv4 addresses, not much they can do.

Just some general observations regarding some of the comments:

It was never the intention to propose superscopes as a solution to all subnetting needs - far from it. As is made clear in the article, it's a proposed solution for a small company on a tight budget - i.e., no new routers, DHCP servers, etc. It's presented as a quick, easy and cost-effective solution. Complicated (as someone suggested)? No - extremely simple.

Also, as stated in the article, what if there's no need for another physical LAN?

Of course you should keep broadcasting in mind - but we're not talking about thousands (or even a thousand) addresses here - it's about a child scope for a Class C address range. I'd say, as a general rule, if you're nearing the halfway mark of the second scope, it's time to start seriously planning another physical subnet.

VLAN's? Again - this is a small company on a budget, remember? You'll need managed switches - expensive items.

"It was never the intention to propose superscopes as a solution to all subnetting needs - far from it. As is made clear in the article, it's a proposed solution for a small company on a tight budget - i.e., no new routers, DHCP servers, etc. It's presented as a quick, easy and cost-effective solution. Complicated (as someone suggested)? No - extremely simple."

My budget would have to be "$0" to do this. I know, because I did it for a bit of time, and it was a complete mess, because I could not get sign off to have another network port installed near my equipment. The $100 for the network drop and the 2 hours of my time in the evening watching the cable guy do it was well worth eliminating the headaches of carrying 2 logical networks on 1 physical wire without VLAN protocols.

"VLAN's? Again - this is a small company on a budget, remember? You'll need managed switches - expensive items."

For under $500 you can buy a managed switch with 24 GigE ports. That is a pretty nice price! And a company that needs less than 24 ports, what are they using? $50 8 port unmanaged switches? If so, they can go buy another $50 switch, and make a VLAN like that! "VLAN" just means "doing with one physical network what you would normally do with two physical networks." If a dinky managed switch is too rich for your blood, then just do it with multitple physical switches. And no to sound crazy, but any network infrastructure large enough to justify any of this is probably going to have managed switches anyways.

J.Ja

What kind of small company with no budget needs 250+ ips?

"What kind of small company with no budget needs 250+ ips?"

A very poor school district. Thats the situation I found myself in.

its useful

I read this article with interest because, as opposed to supernetting, I wouldn't have to track down all the static IP devices on the network and change them. The problem, then, is that these instructions don't appear to work when I perform them on my Windows 2000 server. Perhaps there's not enough detail, but I can't get the new scope to be recognized on the network. And it's hard to find much other documentation about superscoping, either.

how to configure vpn server in windows server2003 step by step

Its nice article. I want to ask that if I created one superscope which defines network (no ip address to lease) and one scope which defines network (new network) as defined above, so would I have to add a router also to make the two networks communicate with each other. So that clients from one network can communicate with clients on another network.

Just pointing out something:

ip address 192.168.1.0 255.255.255.0

Is a subnet number itself and not an actual IP. This would fail to work on any platform when attempting to configure. Neither the subnet number or the broadcast number can be used as an Interface IP.