Persistent connections

The capability to establish persistent connections was added to the product.

Clients/Relays behind firewall or NAT

Firewalls or NAT might prevent the BigFix Query function from working properly because the UDP notification, with which a parent relay delivers the query to the child clients, cannot usually reach the clients. Unlike other product functions, the BigFix Query cannot take advantage of client polling to overcome this restriction in the downstream communications.

This restriction is overcome by establishing a persistent TCP connection between the parent relay and at least one of its child clients. The persistent connection, which is always initiated by the client, is used by the relay to send UDP notifications to all clients in the same subnet of the persistently connected client (PCC).

The same issues can occur on connections between a parent Relay and its child Relays. Also, in this case, the solution is to establish a TCP persistent connection between the parent relay and the child relay.