Enlinkd

The enhanced link daemon collects topology information via SNMP to determine connections between nodes. The daemon essentially asks each device the following question: "What is the network topology, from your point of view?"

The enlinkd discovery process tries to discover bridge domain links using the data coming from all collected bridge forwarding tables.

The enlinkd topology updaters correlate all collected topology data and use it to generate a global topology map of your network.

How it works

Table 1. Enlinkd configuration file overview
File	Description	Reload Event	Restart Required
enlinkd-configuration.xml	Configures generic behavior of enlinkd.	Yes	No

Table 2. Enlinkd log file overview
File	Description
enlinkd.log	Logs relating to enlinkd server events.

Configuration

If multiple link discovery protocols are enabled, links will be discovered for each enabled protocol. The topology map visualizes links for each discovery protocol. For example, if you start both the CDP and LLDP discovery protocols, the web UI visualizes a CDP link and an LLDP link.

Enhanced linkd supports a priority executor to collect SNMP data from devices. Data collection is scheduled for each node and protocol and put into a priority executor running queue. The data collection is performed according to the priority assigned.

Restart enlinkd or Meridian to apply configuration changes.

Table 3. enlinkd-configuration.xml parameters
Attribute	Description	Default
Integer
threads	Number of parallel threads used by schedulables.	3
executor-queue-size	The initial queue size of the priority executor.	100
executor-threads	Number of parallel threads used by priority executor.	5
initial_sleep_time	Amount of time (in milliseconds) to wait before starting collectors after Meridian is launched.	60000
cdp_rescan_interval	Interval (in milliseconds) for Cisco Discovery Protocol (CDP) links discovery.	86400000
lldp_rescan_interval	Interval (in milliseconds) for Link Layer Discovery Protocol (LLDP) links discovery.	86400000
bridge_rescan_interval	Interval (in milliseconds) for Bridge Protocol data collection.	86400000
ospf_rescan_interval	Interval (in milliseconds) for Open Shortest Path First (OSPF) links discovery.	86400000
isis_rescan_interval	Interval (in milliseconds) for Intermediate System to Intermediate System (IS-IS) links discovery.	86400000
topology_interval	Interval (in milliseconds) for the topology updaters.	30000
bridge_topology_interval	Interval (in milliseconds) for the bridge link discovery.	300000
discovery-bridge-threads	Number of threads used for running bridge link discovery.	1
max_bft	Maximum number of bridge forwarding tables (BFTs) that can be stored in memory for discovery.	100
cdp-priority	The priority for running CDP link discovery.	1000
lldp-priority	The priority for running LLDP link discovery.	2000
bridge-priority	The priority for running Bridge data collection.	10000
ospf-priority	The priority for running OSPF link discovery.	3000
isis-priority	The priority for running IS-IS link discovery.	4000
Boolean
use-cdp-discovery	Enable or disable CDP discovery protocol.	true
use-bridge-discovery	Enable or disable bridge discovery protocol.	true
use-lldp-discovery	Enable or disable LLDP discovery protocol.	true
use-ospf-discovery	Enable or disable OSPF discovery protocol.	true
use-isis-discovery	Enable or disable IS-IS discovery protocol.	true
disable-bridge-vlan-discovery	Enable or disable discovery of VLANs.	false

Specifying "false" with a use-{protocol}-discovery attribute deletes persisted protocol data.

The first run of the bridge discovery process is scheduled for initial_sleep_time + bridge_topology_interval. The first run of the updaters is scheduled for 0L.