VMware vRealize Network Insight provides customers intelligent operations for software-defined networking and security. It helps customers to build an efficient, always-on, and secure network infrastructure across different cloud infrastructures. We can plan, design, and deploy micro-segmentation to have visibility across virtual and physical networks. It is very useful in managing VMware NSX deployments and is available as a service offering as VMware Network Insight. vRNI polls third-party devices periodically (between 5 and 10 minutes on average) on a read-only basis. The protocols used include Secure Shell (SSH), Simple Network Management Protocol (SNMP), and Representational State Transfer (REST).

vRNI administrators must configure the vRNI data source interfaces with the read-only credentials that have been predefined on these devices. Additionally, vRNI must be able to access these devices where there are no firewalls and other types of security restrictions (specific to these protocols). In particular, SNMP is typically configured as highly restrictive. In most cases, the vRNI proxy node, in which the SNMP read-only requests are made, is commonly located locally, within the same layer-2 management network, as the third-party devices it needs to poll.

vRNI is not polling these devices in real-time, nor is vRNI listening to or collecting SNMP traps or log data. vRNI is a time-based analytics product and is again polling data every 5-10 minutes (depending on the device and use cases) in support of the use cases offered in this product. The following shows various ways of collecting data for the vRNI dashboard:

• SSH: vRNI uses SSH version 2.0 to access the third-party data source(s). Third-party devices are polled every 10 minutes by default (except for Brocade VDX, which is polled every 15 minutes). No persistent session is maintained.
• REST: vRNI also uses the REST APIs provided by the data source(s). Third-party devices are polled every 10 minutes by default. No persistent session is maintained.
• REST/SSH user credentials and privileges: vRNI requires read-only third-party device credentials (passwords) to access the REST and SSH data. These passwords are added when configuring the third-party data provider within the vRNI user interface. 
• SNMP: vRNI uses SNMP to collect metrics information from third-party devices (switches, routers, firewalls, and so on). The third-party devices much have SNMP enabled and be accessible from vRNI. vRNI queries the device(s) every five minutes to collect the metric information.

Depending on the exact SNMP version used, different parameters are needed:

• SNMP version 2C: Needs the SNMP community string configured on the switch
• SNMP version 3: Needs all of the credentials of the user authorized to poll the SNMP service on the switch