When you first deploy the Tanium Client to an endpoint, the client initiates a connection to Tanium™ Cloud. During initial registration, the Tanium Client establishes a unique ID, andTanium Cloud sends it the latest client settings, a list of nearby peers, and the latest definitions for sensors, questions, and scheduled actions. By default, the initial registration status is configured to reset at randomized intervals of two to six hours, forcing the Tanium Client to re-initialize registration. Repeating the initial registration ensures thatTanium Cloud applies the latest settings and the clients select optimal peers.
The Tanium Client also re-registers withTanium Cloud through a normal registration, which occurs by default at a randomized interval of 30 to 90 seconds. During a normal registration, the Tanium Client reports its current state of questions, actions, and settings toTanium Cloud. In response,Tanium Cloud sends new questions, actions, or settings to apply. In environments with numerous endpoints, normal registrations are the primary way that Tanium Clients receive new questions, actions, and settings.
Client peering
In an enterprise network, Tanium Clients establish peer relationships with each other in a linear chain. Peer connections are continuous, long-lived connections that the clients use to exchange Tanium messages and files. During registration,Tanium Cloud sends the Tanium Client a peer list of other Tanium Clients with which it can try to establish a peer connection. The Tanium Client uses the list to determine which peers are the most optimal neighbors within the linear chain.
By design, one forward leader and one backward leader terminate opposite ends of the linear chain. Other than at registration, only leaders establish direct connections withTanium Cloud.Tanium Cloud passes sensors, questions, and scheduled actions to the backward leader, which passes them to its forward peer, which in turn passes them to its forward peer, and so on, until they reach the forward leader. The forward leader returns the question answers and the scheduled action statuses toTanium Cloud.
Tanium Clients establish outgoing connections to backward peers for file distribution (see File distribution).
Figure 1: Tanium Client linear chain
Forward and backward reflection
Tanium peer communication is designed to accommodate new clients that come online, to route around clients that are removed or stop communicating effectively, and to reflect around network-level blockages, such as firewall blocking. Forward reflection occurs if a Tanium Client cannot establish an outgoing connection to a forward peer in its peer list: the client establishes its forward connection toTanium Cloud instead and becomes a forward leader. Similarly, backward reflection occurs if a Tanium Client cannot establish an outgoing connection to a backward peer: the client establishes a backward connection toTanium Cloud and becomes a backward leader.
LAN and WAN connections
Client peering results in a profound reduction in connections and bandwidth over WAN links. The following figure illustrates the proportions of the savings in a large enterprise network that has subnets in a data center, headquarters, and branch office, as well as VPN connections from remote workers. Other than during registration, only the remote VPN clients and leaders, depicted in bright red, connect toTanium Cloud over the WAN (the internet, in this example). The remaining clients, depicted in darker red, share data over peer connections on the LAN for each subnet.
Figure 2: Client peering in an enterprise network
Satellites
Satellites are specific Tanium Clients that you designate to run certain targeted, secure workloads on behalf of Tanium Cloud, such as non-line-of-sight scans in Discover or remote authenticated scans in Comply.
Figure 3: Tanium Client designated as a satellite
For example, suppose you have a lab network with unmanaged endpoints on a subnet separated from your main network, and you want to use Comply to perform scans on the lab endpoints. Also suppose you are using a managed endpoint with multiple network interface controllers (NICs) to bridge the lab subnet to the main network. You can designate that endpoint as a satellite and then configure Comply to use it to perform scans on the unmanaged endpoints.
Because Tanium Cloudmight need to send sensitive, encrypted data (such as credentials) to a satellite when running a workload, you must verify each endpoint that you designate as a satellite to prevent spoofing attacks. Any such sensitive data is never sent using the linear chain, nor is it stored on-disk on the satellite.
Designating and using satellites requires Direct Connect version 2.1 or later.
Tanium Cloud distributes files to managed endpoints when you deploy actions that use those files. For example, if you deploy an action to upgrade Windows,Tanium Cloud distributes a package that includes the Windows patch file. Tanium Clients running on the endpoints optimize the file distribution process through peering and caching.
File distribution among peers
Peering reduces the number of files thatTanium Cloud distributes over WAN links. Instead of sending files to all managed endpoints,Tanium Cloud sends files only to the backward leader of each linear chain. Each backward leader then relays the files over a high-speed LAN connection from one forward peer to another until they reach the forward leader.
Chunk caching
Caching enables clients to redistribute files in multiple small pieces known as chunks. Each client maintains an local cache of the file chunks thatTanium Cloud previously distributed to the linear chain. When the same files are requested later (for example, when an action runs again), clients can use the cached chunks, instead of requesting thatTanium Cloud redistribute the files again.
TLS
Tanium Cloud supports Transport Layer Security (TLS) for encrypted communication in connections from Tanium Clients toTanium Cloud. Tanium Client 7.4 or later uses TLS communication by default between client peers. For details, see the Tanium Core Platform Deployment Reference Guide: Setting up TLS communication.
