Re: Need more IP addresses

Steve Gr wrote:
Hi,

I have a single subnet 192.168.20.0, network mask 255.255.255.0
There are about 200 IP addresses in use, and I have a lot of new equipment coming that needs IP addresses.
My network understanding is a bit sketchy. I know that I can achieve more addresses by putting part of the network onto a different IP range and routing between them. I've done that before, but that was for a different location within the company and was achieved using a VPN router that also acted as a DHCP server.
Is the segmenting best done at a convenient physical part of the network (ie put all the devices attached to one cabinet onto a different IP range)? In which case how do the devices at that part of the building get a different IP from the DHCP server?

Thanks,
S

If it really is one subnet, I think you merely need to use a different subnet mask to define a larger range. Have a play with this:
http://www.subnet-calculator.com/

I'd think it would be useful to use addresses which make it clear which physical part of the network they inhabit, so you could have another floor on 192.168.21.0 and bodge the subnet mask (everywhere) so this range was seen as the same subnet. You'll need a DHCP server for each distinct subnet - most routers can provide this facility.

See also http://www.faqs.org/rfcs/rfc3330.html
... and note the "private use networks" (by convention, not passed through routers) in section 3 "Summary Table". By the way "/8" means a subnet mask of 8 bits, ie 255.0.0.0, "/16" means "255.255.0.0" - you get the idea.

Disclaimer: there are experts here and I am NOT one of them!

Phil, London
.

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