The discovery process for network devices is divided into multiple Tasks. The TASK is a data collection related to a specific network protocol or technology (MPLS, Transceivers, ARP Table, Spanning-Tree Protocol, Multicast, or VXLAN). Each task consists of 1 or more operational commands (CLI or API). You can find the list of all Discovery Tasks in the Feature matrix.
Some fundamental TASKS are critical for discovery and topology calculations (Neighbors, ARP, Mac, RIB, etc.).
The Discovery Tasks settings are introduced in version 3.7.0. Since then, the user can manipulate specific tasks for the discovery process to avoid extra data collection (when particular protocols are not present on the network) or avoid specific operational commands to be executed on specific hardware platforms.
Disabling TASKS will reduce the level of information collected by IP Fabric. If some fundamental TASKS are disabled, it can affect the topology or Path Lookup results.
By default, there are three main Discovery Task rules in the platform:
|Rule Name||Rule Description|
|Disable Pagination||By default disabled for F5 devices - command is modifying the configuration and can break cluster synchronization.|
|Transceivers||By default disabled for all vendors - certain Cisco platforms may be affected by a memory leak bug and lead to device crash or hung VTY line. More at Known Issues > Cisco|
|NTP||By default disabled for Cisco Firepower - on some versions a Firepower bug may freeze the CLI session|
In the following example, we are creating a rule to disable OSPFv3 on Juniper EX. The test for the rule reveals one match, the HWLAB-JEX2200-SW1 switch: