SDN Controller Programming Guide

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6 Built-In Applications
The HP VAN SDN Controller ships with a default set of core network service components, which
provide an out-of-box experience in terms of enabling connectivity across network applications in
the Openflow network. The details of each are captured below
Device Node Manager
Node network service component is responsible for creating and maintaining the ARP Table. It
also maintains the list of end points or end hosts. An ARP table is maintained for each VNET. The
ARP table contains the MAC address for each host IP address present on the VNET. It does not
contain router proxy ARP entries for IP addresses on remote networks. Orchestration software will
configure a DHCP server or statically assign IP addresses to systems as they are deployed.
The ARP table sample data as shown in Table 7.
Table 7 ARP Table
IP Address
MAC
Vid
SwitchDpid
Port
10.250.100.1
00:af:cd:12:10:01
100
00:ae:c7:de:02:01:02:03
3
10.250.100.2
00:af:cd:12:10:20
110
00:ae:c7:de:02:01:02:03
4
Node Manager listens for PACKET_IN messages. Whenever PACKET_IN message is received by
the Node Manager Subsystem of the controller, it uses the following methods in order to build its
ARP and Node Table structures.
 It ignores the packet if the destination MAC Address is Multicast or broadcast.
 The connected port is identified by using Link Discovery/ Topology module.
 It extracts the source MAC Address from the Ethernet packet.
 It extracts the IP Address from the ARP or from DHCP reply packet. (The HP VAN SDN
Controller 1.6 added IP learning to this list).
The Node Manager updates the existing ARP Tables using the IP Address as the key if it exists
otherwise new entry is added to the corresponding table. Node Manager also provides certain
configurable parameters which can be adjusted as per the network deployment:
 Enable or disable notifications for nodes added, removed or changed (“notify_listeners”) :
Node Manager provides a facility to send node event information to registered listeners. The
nodes events are node add, delete and modify. However, the notification process is
performance intensive, and therefore switched “off” by default. If the administrator wants to
notify the registered listeners of the node events, this parameter can be turned “on”.
Services published by Node Manager Service
Node Manager Network component publishes following API via OSGI declarative services and
REST API. The published API can be broadly categorized in two sub categories:
 IP Address Control functionality