Configure a GRE Topology for a VLAN

Configure a Generic Routing Encapsulation (GRE) tunnel topology for a given VLAN and assign Tunnel Concentrator instances to the VLAN.

Optionally, you can assign rules that manage the volume of multicast and broadcast traffic that crosses Tunnel Concentrator. For example, you can limit multicast traffic to a defined set of multicast addresses and broadcast traffic to essential broadcasts only.

Log in to ExtremeCloud IQ Controller.
Go to Configure > Policy > VLAN.
Configure the following parameters:

VLAN Name
Name of the GRE VLAN
Mode
Select GRE for a Generic Routing Encapsulation (GRE) tunnel.
VLAN ID
The ID of the VLAN. This value must be unique.
Tagged
Specify if the egress port traffic is tagged or untagged. Most GRE VLAN topologies must be tagged. Each concentrator can support only one untagged topology. Select Tagged to tag the topology.
Tunnel Concentrators
List of Tunnel Concentrators.
Select a concentrator from the list, then select Add. You can add up to three concentrators to a single topology. When more than one termination point is added to the list, failover is supported.

The order of the termination points is significant. The primary concentrator must be the first termination point in the list. The AP issues a ping request to the first termination point. If that request fails, it pings the second point, and then the third point. With this organization, you can use the same three concentrators for multiple VLANs, and by varying the termination point order for each VLAN, you can balance the traffic load.
Note
It is a best practice to configure more than one Tunnel Concentrator per VLAN topology for failover. A topology that uses a single generic (non-encrypted) GRE tunnel, without configured backups, is not using the available mechanisms to detect if a Tunnel Concentrator is down. Therefore, no AP alarms, related to the tunnel connectivity, are generated for such a topology.

Load Balance
This checkbox is visible only when the list of concentrators has more than one element. Check Load Balance to load balance APs between concentrators.
(Optional). To configure rules for broadcast and multicast traffic, select Advanced and configure the following:
1. Select Multicast Bridging if you want to be able to forward multicasts between the wired and wireless sides of the AP.
2. If you enabled multicast bridging and want to customize a multicast rule, select Add New Rule and configure the following:
  
  IP
  Enter the multicast IP address (e.g., 224.0.0.5) or network address (e.g., 224.0.0.0) that identifies a range of allowed multicast addresses.
  CIDR
  For a network address, enter the number of network bits (e.g., 27) to define the network and host portion of the allowed range. All multicast addresses that are encompassed by the range are allowed.
  Wireless Replication
  Select this option to allow wireless replication of multicast packets. By default, this field is selected.
3. If you enabled multicast bridging and want to assign a system default multicast rule, select Add Predefined Rule, select the rule, and then select Add.
4. Select Block Non-Essential Broadcast Traffic if you want Tunnel Concentrator to block all broadcast traffic, except for DHCP and ARP (this is the default setting). Otherwise, Tunnel Concentrator floods broadcast traffic to all APs.
5. Select Close.
Select Save.