However, the attacker has full control over TTL, Source Port, MTU, Sequence number, and Window parameters in the SYN packet. This mode is less likely to be noted by IDS, but since the connection is never fully completed, it cannot gather data or banner information. Open ports respond with a SYN|ACK and closed ports respond with ACK|RST or RST. (Windows XP/2000 only) This mode sends out a SYN packet to the target port and listens for the appropriate response. This mode combines the previous two modes into one operation. This mode is also easily recognized by IDS. It can save any data or banners returned from the target. The absence of that message indicates either the port is used, or the target does not return the ICMP message which can lead to false positives. This mode sends a short UDP packet to the target's UDP ports and looks for an ICMP Port Unreachable message in return. This mode is the most accurate for determining TCP services, but it is also easily recognized by Intrusion Detection Systems (IDS). This mode makes a full connection to the target's TCP ports and can save any data or banners returned from the target. The types of port connections supported are:
0 kommentar(er)
