DHCP superscopes and adding a 2nd network range

[loki]

Hey all,

I've got a bit of a question.

Say I have a newtork thats running out of addresses and I want to add another IP range, what would be the best method to go about this. This really stems from reading up on superscopes and adding a 2nd scope to a network.

Say i've got 192.168.1.0/24 and I want to add 192.168.2.0/24 to my subnet. How would the two networks talk to each other?

I can see how a superscope works for servicing a remote subnet via relay, but I just can't get my head around how they will comunicate on a local subnet. Surely if one client on the 1st range wants to contact a client on 2nd range it has to do it via IP and so it goes to the default gateway. How is the router going to deal with the 2nd range when it's setup for the 1st? Is this something that's RAS specific?

Cheers for any help you can give.

[Steve]

In theory can you not have a subnet mask of 255.255.0.0 (192.168.0.0/16) and so have 192.168.0.1 - 192.168.255.254 as your network?

Edit: Or even 255.255.254.0 (192.168.0.0/23) giving you 192.168.0.1-192.168.1.254

[Moby-Dick]

yep as Steve said , go for a larger subnet failing that you'll need some routing between the subnets if you were to have 2 of them

[loki]

Microsoft definitely detail the above as a plausable way to manage an increase in users. I'm like yourselves though I can't see how it works. Looks like it's back to the books.

[i4000]

In your scenario, whilst you could defintiely achieve what you want with superscopes and dish out IP addresses in both the 192.168.1.0/24 and 192.168.2.0/24 ranges (on a single lan segment), but machines from each range would not be able to talk directly to each other becuase of your subnet masks. You would need some form of routing, this can take the form of a classic router or, if you have decent switches, you can utilise layer 3 switching i.e. the switch acts as a router between the subnets. You would need to check your switches to see if they support this.

If you don't have layer 3 switches then the easiest solution would be to shift you subnet mask to the left a bit i.e. if you are currently using 192.168.0.1/24 then change to 192.168.0.1/23 (a subnet mask of 255.255.254.0) this will double the amount of possible machines on the subnet.

Alternatively, as Steve says, just switch from a class C to class B (i.e. 255.255.0.0) subnet mask.

[3xH]

Microsoft definitely detail the above as a plausable way to manage an increase in users. I'm like yourselves though I can't see how it works. Looks like it's back to the books.

Not quite sure what your saying there, but jump into a book that talks about subnetting and this should start to make more sence.

[digit]

You could consider Variable Length Subnet Masking and create subnets only to the size that you require and eliminate the waste of IP addresses as well.

This page from TCP/IP Guide explains it quite nicely:

http://www.tcpipguide.com/free/t_IPV...askingVLSM.htm

Alternatively if you have access to the cisco academy pages you can get a very in depth discussion about it.