Replication errors: agent communication

The following errors occur when network connectivity issues prevent communication between the AWS Replication Agent, replication server, and AWS Elastic Disaster Recovery service endpoints. Each section describes the error, its cause, and resolution steps.

Error: Agent not seen

Error code: AGENT_NOT_SEEN

The source server shows a Disconnected status in the AWS Elastic Disaster Recovery console.

Cause: The AWS Elastic Disaster Recovery service has lost communication with the AWS Replication Agent on the source server.

Resolution:

Console

To resolve agent not seen errors (console)

1. Open the AWS Elastic Disaster Recovery console and check the source server status.

2. Verify that the AWS Replication Agent is running on the source server.

   • Linux: Run systemctl status aws-replication-agent.

   • Windows: Open Services and verify that the AWS Replication Agent service is running.

3. Verify that the source server can reach the AWS Elastic Disaster Recovery endpoint on TCP port 443.

CLI

To resolve agent not seen errors (CLI)

1. Run the following command to check the source server state:

   aws drs describe-source-servers \
       --filters sourceServerIDs=source-server-id \
       --query "items[0].{State:dataReplicationInfo.dataReplicationState,Error:dataReplicationInfo.dataReplicationError.error,LastSeen:lastLaunchedInstance}"

2. Verify that the agent is running on the source server.

   • Linux:

     systemctl status aws-replication-agent

   • Windows:

     Get-Service -Name AwsReplicationService

3. Test TCP 443 connectivity to the AWS Elastic Disaster Recovery endpoint.

   • Linux:

     curl -v https://drs.region.amazonaws.com

   • Windows:

     Test-NetConnection -ComputerName drs.region.amazonaws.com -Port 443

Note

If this error appears on the recovery dashboard, verify that the AWSElasticDisasterRecoveryRecoveryInstancePolicy managed policy is associated with the recovery instance IAM role.

Error: Failed to authenticate with service

Error code: FAILED_TO_AUTHENTICATE_WITH_SERVICE

Cause: The replication server cannot reach the AWS Elastic Disaster Recovery endpoint on TCP port 443. This is a staging area network issue.

Resolution:

Console

To resolve authentication errors (console)

1. Open the AWS Elastic Disaster Recovery console and check the staging area subnet configuration for the affected source server.

2. Launch a test Amazon EC2 instance in the staging area subnet.

3. From the test instance, verify TCP 443 connectivity to the AWS Elastic Disaster Recovery endpoint (drs.region.amazonaws.com).

CLI

To resolve authentication errors (CLI)

1. Run the following command to retrieve the staging area network configuration:

   aws drs get-replication-configuration \
       --source-server-id source-server-id \
       --query "{Subnet:stagingAreaSubnetId,SGs:stagingAreaTags}"

2. Launch a test instance in the staging area subnet and verify TCP 443 connectivity to drs.region.amazonaws.com.

Error: Failed to connect agent to replication software

Error code: FAILED_TO_PAIR_AGENT_WITH_REPLICATION_SOFTWARE

Cause: AWS Elastic Disaster Recovery cannot provide the replication server and agent with the information they need to communicate. This indicates a network connectivity issue between the agent, replication server, and the AWS Elastic Disaster Recovery endpoint.

Resolution:

To resolve agent pairing errors

1. Verify network connectivity between the source server (where the agent runs) and the replication server in the staging area.

2. Verify that both the source server and the replication server can reach the AWS Elastic Disaster Recovery endpoint on TCP port 443.

3. If the issue persists, contact AWS Support.

Error: Failed to establish communication with replication software

Error code: FAILED_TO_ESTABLISH_AGENT_REPLICATOR_SOFTWARE_COMMUNICATION

Cause: Network connectivity issues exist between the agent and the replication server.

Resolution:

To resolve communication errors

1. Verify network connectivity between the agent on the source server, the replication server in the staging area, and the AWS Elastic Disaster Recovery endpoint.

2. Verify that TCP port 1500 is open between the source server and the replication server.

Important

During failback, verify that TCP port 1500 is open for inbound traffic on the recovery instance security group.

Error: Failed to connect agent to replication server

Error code: FAILED_TO_CONNECT_AGENT_TO_REPLICATION_SERVER

Cause: The agent cannot establish a data replication connection with the replication server over TCP port 1500.

Resolution:

Console

To resolve replication server connection errors (console)

1. Open the Amazon EC2 console and locate the security group associated with the staging area replication server.

2. Verify that the security group allows inbound TCP traffic on port 1500.

3. Check the network ACL for the staging area subnet to confirm it allows inbound TCP traffic on port 1500.

CLI

To resolve replication server connection errors (CLI)

1. Retrieve the security group IDs for the replication configuration:

   aws drs get-replication-configuration \
       --source-server-id source-server-id \
       --query "replicationServersSecurityGroupsIDs"

2. Verify that the security group allows inbound TCP port 1500:

   aws ec2 describe-security-groups \
       --group-ids sg-id \
       --query "SecurityGroups[].IpPermissions[?FromPort==`1500`]"

3. Test connectivity to the replication server on port 1500.

   • Linux:

     nc -zv replication-server-ip 1500

   • Windows:

     Test-NetConnection -ComputerName replication-server-ip -Port 1500

Error: Unstable network

Error code: UNSTABLE_NETWORK

Cause: Network connectivity between the source server and the replication server is intermittent.

Resolution:

To resolve unstable network errors

1. Verify that network connectivity between the source server and replication server is stable.

2. Run the network bandwidth test to identify bandwidth or latency issues.

Error: Failback client not seen (replication)

Error code: FAILBACK_CLIENT_NOT_SEEN

Cause: A network connectivity issue is preventing the Failback Client from communicating with the AWS Elastic Disaster Recovery endpoint.

Resolution:

To resolve Failback Client connectivity errors

1. Verify that the Failback Client can reach the AWS Elastic Disaster Recovery endpoint on TCP port 443 (drs.region.amazonaws.com).

2. Check security group rules and network ACLs to confirm outbound TCP 443 traffic is allowed.

For more information, see Failback Client troubleshooting.