MPLS VPN-Tagging Server discovery in the Alcatel-Lucent environment shows the design architecture of MPLS VPN overlapping IP discovery in the Alcatel-Lucent environment.

Figure 1. MPLS VPN-Tagging Server discovery in the Alcatel-Lucent environment

The MPLS VPN-Tagging Server sends CLI discovery requests to the Adapter for Alcatel-Lucent 5620 SAM EMS (the Adapter) in an attempt to discover VRF-based network connections for Lucent-Alcatel routers or switches. When the MPLS VPN-Tagging Server discovers these connections, it sends the connection information to IP Availability Manager so that IP Availability Manager is able to distinguish overlapping IPs on the same device.

Overlapping IP discovery of Alcatel-Lucent devices is triggered in any of the following ways:

  • When the MPLS VPN-Tagging Server starts up.

    At startup, the MPLS VPN-Tagging Server imports a list of Alcatel-Lucent devices from its source IP Availability Manager and performs a full discovery. The devices are identified in the Global_TopologyCollection objects that the Adapter creates in IP Availability Manager.

  • When the MPLS VPN-Tagging Server receives, from IP Availability Manager, a DiscoveredLastAt attribute update for a Global_TopologyCollection object.

    The Adapter changes the date of a global object’s DiscoveredLastAt attribute whenever the Adapter:

    • Connects to IP Availability Manager and creates the global object.

    • Adds new devices to the global object.

      The MPLS VPN-Tagging Server subscribes to DiscoveredLastAt attribute updates.

  • When the MPLS VPN-Tagging Server receives, from the Adapter, a RouteChangedLastAt attribute update for an Alcatel-Lucent device.

    The Adapter sets a device’s RouteChangedLastAt attribute to a new date whenever the Adapter learns of a new or changed route for the device. The MPLS VPN-Tagging Server subscribes to RouteChangedLastAt attribute updates.

    When the MPLS VPN-Tagging Server receives a RouteChangedLastAt attribute update for a device, it places the device in its discovery queue. During the next scheduled full-discovery interval, as defined in the BASEDIR/smarts/conf/vpn-tagging/vpn-tagging.conf file, the MPLS VPN-Tagging Server discovers the device.

    When initiating a discovery of an Alcatel-Lucent device, the MPLS VPN-Tagging Server sends to the Adapter a CLI request that includes the device’s name. The Adapter executes the request and returns the output to the MPLS VPN-Tagging Server.

    A CLI request contains the following CLI command:

    show router <VRF name> route-table
    

    The execution of the CLI command yields the IP route-distinguisher tag and other related network connection information for the target device. The MPLS VPN-Tagging Server writes that information to IP Availability Manager’s Network Connection table.