Managing subnets using OpenStack Horizon¶

Create a subnet¶

Under Project, click Network and then Networks in the sidebar menu.
Press the name of the network to which you want to add the subnet.
Press the small dropdown next to Edit network in the top right corner. Select Create subnet
Name your subnet.
Under Network Address you need to input the address in CIDR notation, more information about this in the Subnet Format. For example 192.168.0.0/24.
Under IP Version, keep IPv4.
Under Gateway-IP you have the option to either set an IP as gateway or not.
If you want a gateway, choose a gateway IP and enter it in the form (we recommend the first IP in the range, if its available) or just leave it blank to select the first available IP.
- If you don’t, leave the field blank and select Disable gateway below.
Press Next
Under Allocation pool, add the DHCP scope. That is, the starting and end addresses you want to auto-assign to hosts using DHCP. Add each pool (we recommend just one pool per subnet) by adding the first address, (comma) last address (with no spaces), for example (if you would use the 192.168.0.0/24 range) 192.168.0.20,192.168.0.254.
Under DNS name servers we recommend adding our servers which are 83.168.225.225 and 83.168.226.226, one per line, in the form. You can use any DNS servers you want though.
Under Host routes, you would add static routes (more information in the Routing between networks article.
Press Create

Under Project, click Network and then Routers in the sidebar menu.
Press the name of the router you want to connect the subnet to.
Press the Interfaces tab on the top.
Press Add interface
Select the subnet in the Subnet dropdown.
Leave the IP address (optional) field blank. This assumes the gateway address on the subnet is not in use somewhere (perhaps by some instance that is running as gateway). Otherwise, the IP address will have to be chosen.
Press Submit