In an NSX environment, VMware Information Sources must be configured for proper operation of a VM-Series firewall to secure east-west traffic. This feature enables the firewall to collect and use dynamic context from VMware environments, such as transitions and changes in VMs and policies, to ensure comprehensive security across virtualized networks. This is crucial for protecting east-west traffic within the data center. The deployment of NSX DFW focuses on distributed firewall capabilities rather than the integration required for the VM-Series firewall.