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- Stopping and restarting the instance after adding a second network interface will release any automatically assigned public IP address. If several interfaces are required where one or more are configured with a public address, use Elastic IP addresses.
- Additionally, adding a second network interface with an IP configuration to a non-Amazon Linux EC2 instance causes traffic flow issues. This occurs in cases of asymmetric routing where traffic to the instance arrives at one network interface and leaves the instance through the other network interface. This is blocked by AWS because of a mismatch between MAC address and IP address. Refer to the AWS documentation and the Charon Cloud Networking Information chapter (section Asymmetric Routing Considerations) for more information. Failure to use the proper steps, may make your instance unreachable!
- If your instance supports enhanced networking there may be naming inconsistencies when adding additional interfaces to a running instance. Please refer to the interface naming section below and the AWS documentation.
- Charon-SSP specific: the NetworkManager is disabled on Charon-SSP AWS marketplace images that are based on Linux 7.x. Therefore, instances based on such images require manually created ifcfg-files in /etc/sysconfig/network-scripts to define the IP configuration for additional interfaces before the Charon Manager can be used to manage it.
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