How can we differentiate the following things?
1.Hub
2.Switch
3.Bridge
4.Router

This post was last modified: 14-07-2008 09:09 PM by Jayson.

1. A Hub operates in the physical layer alone. This means that it just sees the voltages on the line. I merely regenerates the input signal on all the output lines.

2. A Switch/Bridge operates in the Data Link Layer - so it obviously has the functionality of a Hub as well. Since the Swich is a Layer 2 device, it can read Layer 2 information such as the MAC (Physical) addresses, the error detection code and the flags that signify the beginning and end of each frame. The switch can thus separate the data into meaningful blocks. Since it can understand MAC (Media Access Control) addresses, it can also try to send the data to the intended destination unlike the Hub which just broadcasts the input on all output lines. Bridges allow heterogenous networks to be linked together (different mediums, different protocols, etc).

3. A Router operates on the 3rd Layer. Hence it can do all that a Hub and Switch can do. In addition, it can read Layer 3 information like the IP address - and hence it can perform IP routing.

A hub can be used in a small network - but cannot scale to larger networks.

A switch can scale better than a Hub - but it cant efficiently serve large networks - because of the way the switch looksup the internal table to route the frame.

A Router can help in segmenting a network into subnetworks and in routing the packets efficiently.

- Hope this helps !!

This post was last modified: 04-07-2008 01:56 AM by Jayson.

why do we have to forward ports on some routers???
but in some there is no option for it.

some of the routers need port forwarding on specific ports for applications like ssh to work while some dont have an option for it!!!!
i would like to know what is port forwarding

This post was last modified: 14-07-2008 09:11 PM by Jayson.

It is 7:41 in the morning now and I am feeling lazy to type a reply. So, I will let Wikipedie come to the rescue... http://en.wikipedia.org/wiki/Port_Forwarding

It seems that everyone is enjoying Networks, as usual. AST and Mr. J are a good combination. :-) I wonder whether anybody would beat Batch of 2006's record for CN :-P The April 2005 CN q-paper was the best question paper that AU ever produced. Wish all the q-papers were like it.