According to the scenario, John does not want to establish a full TCP connection. Therefore, he will use the TCP SYN scanning technique. TCP SYN scanning is also known as half-open scanning because in this type of scanning, a full TCP connection is never opened. The steps of TCP SYN scanning are as follows:
1.The attacker sends a SYN packet to the target port.
2.If the port is open, the attacker receives the SYN/ACK message.
3.Now the attacker breaks the connection by sending an RST packet.
4.If the RST packet is received, it indicates that the port is closed.
This type of scanning is hard to trace because the attacker never establishes a full 3-way handshake connection and most sites do not create a log of incomplete TCP connections.
Answer option C is incorrect. In TCP SYN/ACK scanning, an attacker sends a SYN/ACK packet to the target port. If the port is closed, the victim assumes that this packet was mistakenly sent by the attacker, and sends the RST packet to the attacker. If the port is open, the SYN/ACK packet will be ignored and the port will drop the packet. TCP SYN/ACK scanning is stealth scanning, but some intrusion detection systems can detect TCP SYN/ACK scanning.
Answer option D is incorrect. TCP FIN scanning is a type of stealth scanning through which the attacker sends a FIN packet to the target port.
If the port is closed, the victim assumes that this packet was sent mistakenly by the attacker and sends the RST packet to the attacker. If the port is open, the FIN packet will be ignored and the port will drop that packet.
TCP FIN scanning is useful only for identifying ports of non-Windows operating systems because Windows operating systems send only RST packets irrespective of whether the port is open or closed.
Answer option B is incorrect. Xmas Tree scanning is just the opposite of null scanning. In Xmas Tree scanning, all packets are turned on. If the target port is open, the service running on the target port discards the packets without any reply. According to RFC 793, if the port is closed, the remote system replies with the RST packet.
Active monitoring of all incoming packets can help system network administrators detect an Xmas Tree scan.

The advantages of a wireless network are as follows:
It provides mobility to users to access a network.
It is easy to connect.
The initial cost to set up a wireless network is low as compared to that of manual cable network. Data can be transmitted in different ways by using Cellular Networks, Mobitex, DataTAC, etc. Data can be shared easily between the wireless devices.

Token Ring

SuperScan is a TCP/UDP port scanner. It also works as a ping sweeper and hostname resolver. It can ping a
given range of IP addresses and resolve the host name of the remote system.
The features of SuperScan are as follows:
It scans any port range from a built-in list or any given range.
It performs ping scans and port scans using any IP range.
It modifies the port list and port descriptions using the built in editor.
It connects to any discovered open port using user-specified "helper" applications.
It has the transmission speed control utility.
Answer option D is incorrect. Nmap is a free open-source utility for network exploration and security auditing. It
is used to discover computers and services on a computer network, thus creating a "map" of the network. Just
like many simple port scanners, Nmap is capable of discovering passive services. In addition, Nmap may be
able to determine various details about the remote computers. These include operating system, device type,
uptime, software product used to run a service, exact version number of that product, presence of some
firewall techniques and, on a local area network, even vendor of the remote network card. Nmap runs on Linux,
Microsoft Windows, etc.
Answer option C is incorrect. Netstat (network statistics) is a command-line tool that displays network
connections (both incoming and outgoing), routing tables, and a number of network interface statistics. It is
available on Unix, Unix-like, and Windows NT-based operating systems. It is used to find problems on the
network and to determine the amount of traffic on the network as a performance measurement.
Answer option A is incorrect. Hping is a free packet generator and analyzer for the TCP/IP protocol. Hping is
one of the de facto tools for security auditing and testing of firewalls and networks. The new version of hping,
hping3, is scriptable using the Tcl language and implements an engine for string based, human readable
description of TCP/IP packets, so that the programmer can write scripts related to low level TCP/IP packet
manipulation and analysis in very short time. Like most tools used in computer security, hping is useful to both
system administrators and crackers (or script kiddies).

The Distance Vector Multicast Routing Protocol (DVMRP) is used to share information between routers to transport IP Multicast packets among networks. It uses a reverse path-flooding technique and is used as the basis for the Internet's multicast backbone (MBONE). In particular, DVMRP is notorious for poor network scaling, resulting from reflooding, particularly with versions that do not implement pruning. DVMRP's flat unicast routing mechanism also affects its capability to scale. Answer option A is incorrect. The Resource Reservation Protocol (RSVP) is a Transport layer protocol designed to reserve resources across a network for an integrated services Internet. RSVP does not transport application data but is rather an Internet control protocol, like ICMP, IGMP, or routing protocols. RSVP provides receiver-initiated setup of resource reservations for multicast or unicast data flows with scaling and robustness. RSVP can be used by either hosts or routers to request or deliver specific levels of quality of service (QoS) for application data streams. RSVP defines how applications place reservations and how they can leave the reserved resources once the need for them has ended. RSVP operation will generally result in resources being reserved in each node along a path. Answer option C is incorrect. A remote procedure call (RPC) hides the details of the network by using the common procedure call mechanism familiar to every programmer. Like any ordinary procedure, RPC is also synchronous and parameters are passed to it. A process of the client calls a function on a remote server and remains suspended until it gets back the results. Answer option D is incorrect. LWAPP (Lightweight Access Point Protocol) is a protocol used to control multiple Wi-Fi wireless access points at once. This can reduce the amount of time spent on configuring, monitoring, or troubleshooting a large network. This also allows network administrators to closely analyze the network.