i have a few IPFire´s here in a few schools which are getting a lot of mobile devices these days.
For those devices i need a second and maybe a third subnet to have enough free IP addresses.
Here is my setup so far:
192.168.1.0/24 = GREEN
192.168.100.0/24 = BLUE (WIFI, IPADS so far, AccessPoints etc.)
192.168.50.0/24 = ORANGE DMZ
PPOE = RED
So for now i would like to have a 192.168.101.0/24 for instance with DHCP and routing inside the BLUE network. A second BLUE subnet if you like.
Is that possible, and if how?
If it is about number of IPs only, just define your BLUE network just as 192.168.100.0/23 or 192.168.100.0/22.
OK, so i will do something like:
I can use the subnet 192.168.100.1-254, 101.1-254, 102.1-254 and 103.1-254, right?
What about DHCP? How can i configure this right in IPFire in that case?
If you use /22, your IP can vary in the last 10(=32-22) bits. That means your net allows 1022 client IPs ( 1024=2^10 minus network address minus broadcast address ).
DHCP allows you do define a subset of these 1022 addresses as dynamic allocated. The remainder can be used for fixed leases ( which I would recommend, it makes things sometimes easier ).
Consider lowering your dhcp renewal time if you have a higher turn over of clients coming and going.
No point in giving a long lease to someone who pops in for an hour a day.
Maybe also consider using a private net in the 172.16.0.0 – 172.31.255.255 range (about 1 million clients) or the 10.0.0.0 – 10.255.255.255 range (~16 million clients)
Another important consideration is the increase in broadcast traffic with all the device discovery going on with bonjour et al.
In a large subnet, make sure both your wireless solution and your switching/routing can handle/mitigate this.
Thanks a lot for all your comments!
I´ve switched now to a CIDR 22 notation and it works like a charm. I have plenty of addresses i can use and a lot of space for switches etc. free.