VLAN IP Ranges

[Gongalong]

Hi folks,

 

This is probably more of a basic IP network question, but I can't spot a better forum for it.

 

We already have three VLANs, with the following scopes 0 = 10.121.244.0 / 255.255.252.0, 100 = 192.168.0.0 / 255.255.252.0, 101 = 172.16.16.0 / 255.255.240.0. They all link to different wireless profiles, and different user groups. I would like to add two more, but what IP ranges should I pick? I'm aware of Class A, B, and C networks, but does it really matter what numbers I pick? The first VLAN predates me and is clearly class A (yet not technically a class A network), the other two were added by a 3rd party while I was here, and are both B and C *shrug*

 

The ideal would be to pick different numeric ranges because we have a Smoothwall, and we already use it to provide DHCP on two of the VLANs. The Smoothwall shows a flat list of leases, they aren't separated by VLAN, so having the two new VLANs in different ranges would be helpful.

 

Any help much appreciated.

 

Thanks

[Steve21]

I mean that's a very odd way of setting up that network. You don't normally mix the 3 classes like that, as you can just re-use the 10. with another range.

 

 

0 = 10.121.244.0 / 255.255.252.0 would be 10.121.244.1-10.121.247.254

 

So you could then use anything else in that list, unless you really wanted a different number then could use 10.120.X.X etc but that depends if your router needs those IPs depending on how big the network is and if you're scoping/NAT behind the firewall

 

Lazyness copy/pasta:

 

Network Address Usable Host Range Broadcast Address:

10.121.0.0 10.121.0.1 - 10.121.3.254 10.121.3.255

10.121.4.0 10.121.4.1 - 10.121.7.254 10.121.7.255

10.121.8.0 10.121.8.1 - 10.121.11.254 10.121.11.255

10.121.12.0 10.121.12.1 - 10.121.15.254 10.121.15.255

10.121.16.0 10.121.16.1 - 10.121.19.254 10.121.19.255

10.121.20.0 10.121.20.1 - 10.121.23.254 10.121.23.255

10.121.24.0 10.121.24.1 - 10.121.27.254 10.121.27.255

10.121.28.0 10.121.28.1 - 10.121.31.254 10.121.31.255

10.121.32.0 10.121.32.1 - 10.121.35.254 10.121.35.255

10.121.36.0 10.121.36.1 - 10.121.39.254 10.121.39.255

10.121.40.0 10.121.40.1 - 10.121.43.254 10.121.43.255

10.121.44.0 10.121.44.1 - 10.121.47.254 10.121.47.255

10.121.48.0 10.121.48.1 - 10.121.51.254 10.121.51.255

10.121.52.0 10.121.52.1 - 10.121.55.254 10.121.55.255

10.121.56.0 10.121.56.1 - 10.121.59.254 10.121.59.255

10.121.60.0 10.121.60.1 - 10.121.63.254 10.121.63.255

10.121.64.0 10.121.64.1 - 10.121.67.254 10.121.67.255

10.121.68.0 10.121.68.1 - 10.121.71.254 10.121.71.255

10.121.72.0 10.121.72.1 - 10.121.75.254 10.121.75.255

10.121.76.0 10.121.76.1 - 10.121.79.254 10.121.79.255

10.121.80.0 10.121.80.1 - 10.121.83.254 10.121.83.255

10.121.84.0 10.121.84.1 - 10.121.87.254 10.121.87.255

10.121.88.0 10.121.88.1 - 10.121.91.254 10.121.91.255

10.121.92.0 10.121.92.1 - 10.121.95.254 10.121.95.255

10.121.96.0 10.121.96.1 - 10.121.99.254 10.121.99.255

10.121.100.0 10.121.100.1 - 10.121.103.254 10.121.103.255

10.121.104.0 10.121.104.1 - 10.121.107.254 10.121.107.255

10.121.108.0 10.121.108.1 - 10.121.111.254 10.121.111.255

10.121.112.0 10.121.112.1 - 10.121.115.254 10.121.115.255

10.121.116.0 10.121.116.1 - 10.121.119.254 10.121.119.255

10.121.120.0 10.121.120.1 - 10.121.123.254 10.121.123.255

10.121.124.0 10.121.124.1 - 10.121.127.254 10.121.127.255

10.121.128.0 10.121.128.1 - 10.121.131.254 10.121.131.255

10.121.132.0 10.121.132.1 - 10.121.135.254 10.121.135.255

10.121.136.0 10.121.136.1 - 10.121.139.254 10.121.139.255

10.121.140.0 10.121.140.1 - 10.121.143.254 10.121.143.255

10.121.144.0 10.121.144.1 - 10.121.147.254 10.121.147.255

10.121.148.0 10.121.148.1 - 10.121.151.254 10.121.151.255

10.121.152.0 10.121.152.1 - 10.121.155.254 10.121.155.255

10.121.156.0 10.121.156.1 - 10.121.159.254 10.121.159.255

10.121.160.0 10.121.160.1 - 10.121.163.254 10.121.163.255

10.121.164.0 10.121.164.1 - 10.121.167.254 10.121.167.255

10.121.168.0 10.121.168.1 - 10.121.171.254 10.121.171.255

10.121.172.0 10.121.172.1 - 10.121.175.254 10.121.175.255

10.121.176.0 10.121.176.1 - 10.121.179.254 10.121.179.255

10.121.180.0 10.121.180.1 - 10.121.183.254 10.121.183.255

10.121.184.0 10.121.184.1 - 10.121.187.254 10.121.187.255

10.121.188.0 10.121.188.1 - 10.121.191.254 10.121.191.255

10.121.192.0 10.121.192.1 - 10.121.195.254 10.121.195.255

10.121.196.0 10.121.196.1 - 10.121.199.254 10.121.199.255

10.121.200.0 10.121.200.1 - 10.121.203.254 10.121.203.255

10.121.204.0 10.121.204.1 - 10.121.207.254 10.121.207.255

10.121.208.0 10.121.208.1 - 10.121.211.254 10.121.211.255

10.121.212.0 10.121.212.1 - 10.121.215.254 10.121.215.255

10.121.216.0 10.121.216.1 - 10.121.219.254 10.121.219.255

10.121.220.0 10.121.220.1 - 10.121.223.254 10.121.223.255

10.121.224.0 10.121.224.1 - 10.121.227.254 10.121.227.255

10.121.228.0 10.121.228.1 - 10.121.231.254 10.121.231.255

10.121.232.0 10.121.232.1 - 10.121.235.254 10.121.235.255

10.121.236.0 10.121.236.1 - 10.121.239.254 10.121.239.255

10.121.240.0 10.121.240.1 - 10.121.243.254 10.121.243.255

10.121.244.0 10.121.244.1 - 10.121.247.254 10.121.247.255

10.121.248.0 10.121.248.1 - 10.121.251.254 10.121.251.255

10.121.252.0 10.121.252.1 - 10.121.255.254 10.121.255.255

 

etc

 

Steve