public UpdateProbeRequest withProtocol(Protocol protocol) {
        this.protocol = protocol.toString();
        return this;
    }
<p>
The updated network protocol for the destination. This can be either <code>TCP</code> or <code>ICMP</code>. If
the protocol is <code>TCP</code>, then <code>port</code> is also required.
</p>

@param protocol
       The updated network protocol for the destination. This can be either <code>TCP</code> or <code>ICMP</code>
       . If the protocol is <code>TCP</code>, then <code>port</code> is also required.
@return Returns a reference to this object so that method calls can be chained together.
@see Protocol
aws-java-sdk-networkmonitor/src/main/java/com/amazonaws/services/networkmonitor/model/UpdateProbeRequest.java