@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(network_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 1, network_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(subnetwork_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 2, subnetwork_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(internalIp_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 3, internalIp_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(externalIp_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 4, externalIp_);
    }
    getUnknownFields().writeTo(output);
  }
<pre>
The external IP to define in the NIC.
</pre>

<code>string external_ip = 4;</code>

@return The bytes for externalIp.
java-vmmigration/proto-google-cloud-vmmigration-v1/src/main/java/com/google/cloud/vmmigration/v1/NetworkInterface.java