LAN Subnet and DHCP


#1

Hello All,

Hardware: Balance 20

I have a need for more then 254 private IP Addresses on a network. Ideally 1016 would be available.

If I set the LAN IP Address to 10.10.0.1 and the subnet to 255.255.0.0
and set DHCP to give out addresses 10.10.0.1 to 10.10.4.254 will 1016 addresses be available?

TIA,

~e


#2

I tend to use this tool for calculating addresses.

http://www.aboutmyip.com/AboutMyXApp/SubnetCalculator.jsp?ipAddress=10.10.0.0&cidr=22


#3

Thanks, yes I know how many addresses are available in Network Class A with a subnet of 255.255.0.0, its 65534 addresses.

My question is can the Peplink balance 20 be configured in this way.

I just edited one of my Balance 20’s by changing the LAN IP Address subnet to 255.255.0.0
and the DHCP to 10.10.0.100 to 10.10.5.250 and was allowed to save it, though I didn’t apply it, so it will probably work.

~eric


#4

Yes absolutely. As long as you use the proper subnet and DHCP range it will save and work as intended.


#5

You can also utilize VLANs which help to segment network clients and traffic. Everything in the same broadcast domain will “hear” everything at layer 2. Depending on your deployment needs VLANs may be something to consider.


#6

Thanks Jeffrey,

It’s WiFi clients in a public setting. Do you think there would be any performance benefit to segmenting?

~eric


#7

Super, thanks Kevin.


#8

Hi Eric,

I believe there would be, yes, especially if there are clients that are frequently joining the network. All broadcast traffic, including DHCP traffic, involves every device on the network segment. By limiting network segments to a smaller range you limit the size of the broadcast area. With inter-VLAN routing enabled everyone on the networks with the option selected can still communicate with one another while avoiding all the broadcast traffic from being exposed to such a large group of clients.

The only potential consideration is that anyone requiring communication with a device on a different network segment will require router, or another device, involvement at layer 3. Although this will most likely not be a factor it is worth mentioning as this will be considered “throughput” and if the device is already heavily tasked it may limit overall performance. Again, most likely not a factor but something to note as a potential consideration.

Thanks Eric!