HP VAN SDN Controller Administrator Guide

configured for the impacted port, thereby causing the packet-ins to

again come to the controller.

Operation notes:

 Does not handle multicast and broadcast traffic

 Does not configure the reverse path along with the forward

path

 Drops packets from sources that the controller has not learned

 Floods packets when their destinations are not known

 Does not support multi-pathing or fast-failover

 Performance is topology-dependent, recommended for 100-

200 node environments

The Path Daemon application uses the Topology Service, Node Servce,

and Flow Service applications. For more on Path Daemon, see Figure

14 Path Daemon Flowchart on page 23.

Path Diagnostics

Determines and verifies the path taken by a specific packet from a

source host to destination host.

 Evaluates flows configured across the switches in the control

domain for diagnosis

 Creates ‘Observation posts’ on every switch in the path that the

packet would take

 Tallys packet_ins from the observation posts to figure out where

a path is broken

 Lists neighbors for any given device

Link Manager

Builds information about links between network elements in the

controller domain. Provides information about the linkages between

network elements and serves as a base for other applications such as

topology, etc. This application maintains a table of source and

destination devices and ports, and transmits LLDP PDUs to all detected

devices.

Note

LinkManager operation requires LLDP to be enabled on

OpenFlow switches in the network.

Operation includes:

 Learning and maintaining all inter-switch links in the control

domain.

 Provideing data used by the controller topology module to