81. What are NetBIOS and NetBEUI?
Answer : NETBIOS is a programming interface that allows I/O requests to be sent to and received from a remote computer and it hides the networking hardware from applications.
NetBEUI is NetBIOS extended user interface. A transport protocol designed by Microsoft and IBM for the use on small subnets.
82. How is Gateway different from Routers?
Answer : Router is used for communicating two different networks and use the best path to reach the destination, whereas, the gateway is the outer interface of the network. if you go to one network to another network then all traffic pass through a gateway.
Likewise, Router is a layer 3 device, which is used for inter network communication and routing purpose but Gateway is an entry & exit point of our network.
83. What is MAC address?
Answer : The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC address is usually stored in ROM on the network adapter card and is unique.
84. What is the difference between bit rate and baud rate?
Answer : The differences between bit rate and baud rate:
Bit rate is measured as a number of data bits transmitted / second in communication channel whereas, Baud rate is measured as the number of times a signal state is changed in a communication channel.
baud rate = (bit rate / N)
where N is no-of-bits represented by each signal shift.
85. What is Project 802?
Answer : It is a project started by IEEE to set standards to enable intercommunication between equipment from a variety of manufacturers. It is a way for specifying functions of the physical layer, the data link layer and to some extent the network layer to allow for interconnectivity of major LAN protocols.
It consists of the following:
802.1 is an internetworking standard for compatibility of different LANs and MANs across protocols.
802.2 Logical link control (LLC) is the upper sublayer of the data link layer which is non-architecture-specific, that remains the same for all IEEE-defined LANs.
Media access control (MAC) is the lower sublayer of the data link layer that contains some distinct modules each carrying proprietary information specific to the LAN product being used. The modules are Ethernet LAN (802.3), Token ring LAN (802.4), Token bus LAN (802.5).
802.6 is a distributed queue dual bus (DQDB) designed to be used in MANs.
86. What is the difference between ARP and RARP?
Answer: Address Resolution Protocol (ARP) is utilized for mapping IP network address to the hardware address that uses data link protocol whereas, Reverse Address Resolution Protocol is a protocol using which a physical machine in a LAN could request to find its IP address from ARP table or cache from a gateway server.
IP address of the destination to physical address conversion is done by ARP, by broadcasting in LAN, however, a Physical address of source to IP address conversion is done by RARP.
Another difference is that ARP Associates 32 bit IP address with 48-bit physical address, but RARP allows a host to discover its internet address after knowing only its physical address.