Add a Subnetwork Space

About this task

When you create a subnetwork for branch sites, you have a choice between making one large parent subnetwork that ExtremeCloud IQ sections into individual segments for each site or a smaller subnetwork that each site reuses. You define the subnetwork type—whether it is for internal, guest, or management traffic—and configure options for DHCP, DNS, NTP, and NAT.

Procedure

  1. Select the plus sign.
  2. Enter an optional description.
  3. Choose a network type from the drop-down list as follows:
    • Internal Use - Routers can apply internal subnetworks to regular users, such as employees or students. DNS and DHCP services are optional. The addressing for internal subnetworks can be unique among all branch sites so that routers can tunnel traffic through a VPN gateway to a central site and to other branch sites without needing NAT. If you decide to replicate the same subnetwork at each site, then routers will require NAT to send traffic between themselves and a VPN gateway.
    • Guest Use - Routers use a subnetwork for guest use for temporary users, such as visitors. DHCP or DHCP relay is required and DNS service is optional. Because guests are not expected to access resources through VPN tunnels at the corporate or other branch sites, the addressing for a guest subnetwork is the same for all routers at all branch sites. Routers do not enable guest traffic to pass through a VPN tunnel to the main site. Guests are only allowed to access the Internet.
    • Management - An Extreme Networks router, and Extreme Networks APs and switches at the same branch site communicate with each other. DNS and DHCP services are required.
  4. Create a unique subnetwork at each site, as follows:
    • Local IP Address Space: Enter the parent IP address scope. The parent scope contains the IP address scopes of all remote sites.
    • Partition the local IP address space into subnetworks: Use the slider to select the best match for how many branch offices you need to configure and how many clients there are at each branch. Select the maximum number of foreseeable branches and be sure the number of clients per branch exceeds the maximum foreseeable number of clients at any one branch. If you cannot fit the maximum number of clients and branches within your chosen parent scope, you must increase the parent scope.
    • Use the first IP address of the partitioned subnetwork for the default gateway: Select to use the first IP address as your default gateway.
    • Use the last IP address of the partitioned subnetwork for the default gateway: Select to use the last IP address as your default gateway.
  5. Replicate the same subnetwork at each site, as follows:
    • Local IP Address Space: Enter the IP address and netmask of the local subnetwork at each branch site, and select either the first or last IP address as the default gateway, depending upon its configuration.
    • Use the first IP address of the partitioned subnetwork for the default gateway: Select this option to use the first IP address as your default gateway.
    • Use the last IP address of the partitioned subnetwork for the default gateway: Select this option to use the last IP address as your default gateway.
    Note

    Note

    If you have any branch sites in your enterprise topology that have overlapping or conflicting IP address schemes, and making changes to those address structures will pose difficulties, you can use NAT on the tunnel interfaces on the routers at each site. The branch routers can then map local subnetworks to different addresses that can be routed through VPN tunnels across your network. With this approach, you can configure the Extreme Networks branch routers, which function as NAT gateways, to map their local subnetwork addresses, one-for-one, to NAT subnetwork addresses. ExtremeCloud IQ maps each host address on the local subnetwork side of the router uniquely to a corresponding network host address on the NAT subnetwork side of the router.

  6. Select SAVE or proceed to Configure Subnetwork Space Advanced Settings.