Subject - Network and Information security I want detailed and clear answers.. I
ID: 3913250 • Letter: S
Question
Subject - Network and Information security
I want detailed and clear answers..
In computer date networks , we use the following devices to direct the traffic among computer in different part of the network.
Hub, Switch , Router and Gateway .
What are the differences among them?
Under what kind of circumstances, we should not be considering to deploy Hubs?
What are the main functions of Gateway? And where we should use Gateway?
What are the functions of Routing Tables ?
What are the differences between MAC address and the IP address?
Explanation / Answer
? What are the differences between Hub, Switch , Router and Gateway?
Hub
A hub is the simplest of the above devices. Any data packet coming from one port is sent to all other ports. It is then up to the receiving computer to decide if the packet is for it. Since every packet is sent out to every computer on the network, there is a lot of traffic generated and wasted transmission.
Applications:
Hubs are typically used on small networks where the amount of data going across the network is never very high.
Switch
A switch connects all ports to each other, like a hub, but a switch examines incoming Ethernet messages to see which port is the intended recipient, and then passes the messages to that port. This way other ports do not unnecessarily receive all traffic.
Router
A router is similar in a switch in that it forwards packets based on address. But, instead of the MAC address that a switch uses, a router can use the IP address. Before forwarding a packet the router will review the destination IP address.
Applications:
In a typical home network, the router provides the connection between the network and the Internet.
Gateway
A gateway is a passage to connect two networks together that may work upon different networking models. They basically works as the messenger agents that take data from one system, interpret it, and transfer it to another system. Gateways can operate at any network layer.
? Under what kind of circumstances, we should not be considering to deploy Hubs?
Hubs forward any data packet coming from one port to all the other ports in the network and hence generate a lot of traffic. Most of this traffic is wasted, since it is intended for only one node but it is sent to all nodes on the network. Hence, hubs should not be deployed in larger networks where the amount of data going across the network is very high.
? What are the main functions of Gateway? And where we should use Gateway?
Gateway connects two computer networks with different network architectures and protocols through Network Address Translation. Gateways are also used to connect networks operating at different transmission speeds.
Applications:
In a workplace, the gateway is the computer that routes traffic from a workstation to the outside network that is serving up the Web pages. For basic Internet connections at home, the gateway is the Internet Service Provider that gives you access to the entire Internet.
? What are the functions of Routing Tables ?
A routing table contains the information necessary to forward a packet along the best path toward its destination.
When a packet is received, a network device examines the packet and matches it to the routing table entry providing the best match for its destination.
The table then provides the device with instructions for sending the packet to the next hop on its route across the network.
Routing tables can be maintained manually or dynamically. Tables for static network devices do not change unless a network administrator manually changes them.
Dynamic routing tables allow devices to "listen" to the network and respond to occurrences like device failures and network congestion.
? What are the differences between MAC address and the IP address?
A MAC address is a number assigned to the Network Interface Card by the manufacturer.
IP address is a number assigned to the connection in a network.
Full Form Media Access Control Address. Internet Protocol Address. Purpose It identifies the physical address of a computer on the internet. It identifies connection of a computer on the internet. Bits It is 48 bits (6 bytes) hexadecimal address. IPv4 is a 32-bit (4 bytes) address, and IPv6 is a 128-bits (16 bytes) address. Address MAC address is assigned by the manufacturer of NIC card. IP address is assigned by the network administrator or Internet Service Provider.