Multi Datacenter Federation

Which protocol do Consul servers use to maintain the WAN gossip pool?

In a multi-datacenter environment, what happens if the 'primary_datacenter' server cluster becomes unavailable?

You have enabled ACL replication between a primary and secondary datacenter. What is the effect of changing an ACL policy in the primary datacenter?

You are troubleshooting a partition between two datacenters. The WAN gossip shows high latency. Which Consul CLI tool provides the best insight into the WAN gossip state?

How do you enable WAN federation between two Consul datacenters that do not share a network?

You are joining two Consul datacenters via WAN gossip. Which command must be executed on a Consul server in the secondary datacenter to initiate the federation?

What is the role of a Consul server in a non-primary datacenter regarding ACLs?

What is the purpose of the 'datacenter' field in the Consul agent configuration?

What happens to the gossip protocol if the 'encrypt' key is mismatched between two datacenters trying to join via WAN?

When configuring ACL replication, where must the 'acl_replication_token' be defined?

You want to ensure that specific services in a remote datacenter are only accessible to certain local services. How can you achieve this?

When using 'prepared_queries' for cross-datacenter failover, what does the 'failover' block allow you to specify?

Which file format is used for Consul configuration?

What is the benefit of using a Mesh Gateway in a multi-datacenter deployment with overlapping IP space?

To verify if two datacenters are connected via WAN, which command shows the remote datacenter's server nodes?

You notice that the KV store is not consistent across datacenters. What is the cause?

When joining a new datacenter to an existing WAN pool, what is the best practice for server versions?

When using multiple datacenters, what is the primary role of the 'consul-template' tool?

What is the recommended number of Consul servers per datacenter to ensure high availability?

Which TWO of the following accurately describe Consul's WAN gossip protocol behavior?

Which TWO of the following are true about Consul datacenters?

Which THREE network considerations are vital for Consul WAN federation?

Which TWO of the following are valid ways to troubleshoot inter-datacenter communication issues?

A platform team operates two Consul datacenters, dc1 (primary) and dc2 (secondary), with ACLs enabled. They have configured token replication using a replication token in dc2. After rotating the replication token in dc1, they update the configuration in dc2 and restart the Consul agents. However, ACL replication stops working and dc2 logs show 'Permission denied'. What is the most likely cause?

A platform team operates a Consul 1.15 cluster with a primary datacenter in us-east-1 and a secondary datacenter in eu-west-1. After configuring ACLs for replication, they update a token policy in the primary datacenter. A security engineer in the secondary datacenter immediately checks the ACL token and finds the old policy still in effect. What is the most likely reason the policy change has not propagated yet?

A company runs Consul 1.15 in three datacenters: dc1 (primary), dc2, and dc3 (secondaries). The operations team wants to ensure that if dc1 becomes unavailable, the remaining datacenters can still authenticate services using existing ACL tokens. They have already configured ACL replication and WAN federation. Which statement best describes the expected behavior of ACL tokens in dc2 and dc3 during a primary datacenter outage?

An operator is configuring a new Consul datacenter that must be able to resolve services in a remote datacenter using the DNS interface. The remote datacenter is already federated and reachable. Which query format should the operator use to resolve a service named 'web' in the remote datacenter 'dc2'?

A cloud engineer is setting up a new Consul 1.15 datacenter that will join an existing WAN federation. The existing datacenter uses a specific gossip encryption key for the WAN pool. Which configuration parameter must be set on the new datacenter's servers to ensure they can participate in WAN gossip?

You are configuring a new Consul datacenter named 'dc2' to join an existing WAN federation with primary datacenter 'dc1' that uses mesh gateways. The WAN is not directly routable between datacenters. Which configuration allows dc2's servers to establish WAN federation through the mesh gateways?

You are deploying a new Consul datacenter and need to configure the servers to join the existing WAN gossip pool. Which configuration parameter should you set on the new servers to specify the addresses of the existing WAN servers?

A platform team operates two Consul datacenters, 'dc1' and 'dc2', and wants operators in dc2 to resolve service names registered in dc1 without a full mesh of local agents. They have already used 'consul join -wan' to link the server agents. Which feature should they rely on for DNS lookups of remote services?

You are deploying Consul servers in a new datacenter that will be a secondary in a federated environment. The primary datacenter is already configured with ACLs enabled and replication is working. You need to ensure the new secondary datacenter can replicate ACLs from the primary. Which configuration must be set on the new secondary's servers?

A Consul operator wants to ensure that if the primary datacenter becomes unavailable, the secondary datacenter can continue to operate for existing services and intentions. Which statement best describes Consul's behavior in this scenario?

A company runs a primary datacenter and a secondary datacenter with ACL replication enabled. During a maintenance window the primary's servers are taken offline for several hours while the secondary remains fully operational. What is the expected behavior in the secondary during the outage?

You are configuring a new Consul datacenter in a multi-datacenter federation. The datacenter must be able to join the existing WAN gossip pool and participate in cross-datacenter service discovery. Which two configuration settings are required on the new datacenter's Consul servers to enable WAN gossip and ensure secure communication? (Choose two.)

You are configuring a Consul secondary datacenter to replicate ACLs from the primary. You have set 'primary_datacenter' and 'acl_replication_token' on the servers. However, replication is failing. Which of the following is the most likely cause?

You have a Consul 1.15 cluster with two datacenters, dc1 and dc2, federated via WAN gossip. You want to use a prepared query to automatically failover to a service in dc2 if the service in dc1 becomes unhealthy. Which configuration in the prepared query is required to achieve this?

You are managing a multi-datacenter Consul deployment with ACLs enabled. The primary datacenter is in dc1, and a secondary datacenter is in dc2. You have configured ACL replication in dc2 using acl_replication_token. After some time, you notice that new ACL tokens created in dc1 are not being replicated to dc2, and the replication status shows 'No known leader'. What is the most likely cause of this issue?

A new engineer is configuring a Consul server agent for a datacenter named 'west' and wants the agent to automatically rejoin the WAN federation after a restart without manual intervention. Which configuration setting should they use?

You are deploying a Consul cluster across three datacenters: dc1, dc2, and dc3. Each datacenter has its own LAN gossip pool and they are all joined via WAN gossip. You want to enable cross-datacenter service discovery so that services in dc1 can discover services in dc2 and dc3. Which Consul feature allows a service in one datacenter to query services in another datacenter without additional configuration?

You are using Consul's DNS interface to query a service named 'web' in datacenter dc2 from a client in dc1. The query returns no results, but you know the service is running in dc2. What is the most likely reason?

An operator is troubleshooting a Consul datacenter that was recently federated with another datacenter. They notice that cross-datacenter service discovery works, but ACL tokens created in the primary datacenter are not being recognized in the secondary datacenter. What is the most likely cause?

An operator has two Consul datacenters, 'dc1' and 'dc2', federated via WAN gossip. They want to query the health of a service named 'web' in dc2 from a Consul agent in dc1 using the HTTP API. Which endpoint should they use?

A Consul 1.15 cluster spans three datacenters: dc1 (primary), dc2, and dc3. The operations team wants to enable cross-datacenter service discovery for a service named 'web' that is deployed in all datacenters. They configure a prepared query with a failover policy. Which statement accurately describes how the failover block in the prepared query affects query results when the local datacenter's 'web' service has no healthy instances?

An operator is configuring a new Consul 1.15 datacenter 'dc3' to join an existing WAN federation with primary datacenter 'dc1'. The operator wants to ensure that dc3 can automatically rejoin the WAN gossip pool after a restart. Which configuration parameter should be set in dc3's server configuration?