Defining a Next Hop Route and OSPF Advertisement

The next hop definition allows the administrator to define a specific host as the target for all non-VNS targeted traffic for users in a VNS. The next hop IP identifies the target device to which all VNS (user traffic) will be forwarded to. Next-hop definition supersedes any other possible definition in the routing table.

If the traffic destination from a wireless device on a VNS is outside of the VNS, it is forwarded to the next hop IP address, where this router applies role and forwards the traffic. This feature applies to unicast traffic only. In addition, you can also modify the OSPF (Open Shortest Path First) route cost.

OSPF is an interior gateway routing protocol developed for IP networks based on the shortest path first or link-state algorithm. Using OSPF, a host that obtains a change to a routing table or detects a change in the network immediately distributes the information to all other hosts in the network so that all will have the same routing table information. The host using OSPF sends only the part that has changed, and only when a change has taken place.

To define a Next Hop Route and OSPF Advertisement:

  1. From the top menu, click VNS.
  2. In the left pane, expand the Topologies pane, then click the Routed topology for which you want to define a next-hop route.
  3. In the Layer 3 area, click the Configure button. The DHCP (Dynamic Host Configuration Protocol) configuration dialog displays.
    Click to expand in new window
    DHCP configuration
    Graphics/Topology-NextHop.jpg
  4. In the Next Hop Address box, type the IP address of the next hop router on the network through which you wish all traffic on the VNS using this Topology to be directed.
  5. In the OSPF Route Cost box, type the OSPF cost of reaching the VNS subnet.

    The OSPF cost value provides a relative cost indication to allow upstream routers to calculate whether or not to use the controller as a better fit or lowest cost path to reach devices in a particular network. The higher the cost, the less likely of the possibility that the controller will be chosen as a route for traffic, unless that controller is the only possible route for that traffic.

  6. To disable OSPF advertisement on this VNS, select the Disable OSPF Advertisement checkbox.
  7. Click Close.
  8. Click Save.