subnetmask issue
 

my self raghu (system admin in Engineering college,banaglore,)

i have network of star topology and subnetmask of 255.255.0.0 i have 3com switch of 40 ports, in department,

if i change the subnet mask to nic card i wont able get internet,


and i have one proxy server for a entire network,

i want to configure my department network separate with a subnet mask of 255.255.255.0, and at the same time i would like get internet also,

what i have to do, how can i configure on linux server,

help me out

thanks before,

hope reply

If you change your networks subnet mask, I assume you have a router between your department and the rest of the networks. What you are doing is simply creating a subnet..

Please give more details about you network, and how you have the router configured between the two networks.

thanks

actually the router and proxy server configured by other department

called E.D.P rest of the college only use the proxy server ip-

address get the internet using the subnet mask of 255.255.0.0


it was cisco router and it was having ip but i dont know ip

the network has configured this way

total departments 28, one of that is my department.

Every departments having 3com switches according to number of

terminal , All the terminal are connected to the switches, the

switches are connected with a one UP link with a cat 5 or 6 able

from EDP department. and the down link will be connected other

department.


the proxy and router is configured with a public ip address

if u want any more details i can provide to u , please ask me any thing esle u want.

Ok, so where do we go from here?

You can't just change a network mask on your NIC without also changing the other network devices on the same network.

So what do you want to do?

One way to change the netmask in your department can be to put a router between your department network and the complete college network.
Other than this I do not think you can and should do it. Messing up with a network not designed by you can be troublesome for both of you guys.
You better talk to the department guys who designed the network before making any changes and then growling over non connectivity.

what i want to do is i want to make myterminal and swicth should have different subnet mask and differ from the other network and also get the internet.

any thing like this we can make it.

switches do not have network masks - they are layer 2 devices, knowing nothing about IP addresses and netmasks.

I don't know what "myterminal" means.

Get another router and place it between your companies router and your department


Make this:

company router <-> switch <-> your deparment computers

look like this:

company router <-> new router <-> switch <-> your deparment computers

Then, behind the new router, you can reconfigure your network as you see fit.

You can't do it with just a switch.

thank u very much,

i got it, sorry to using ternimal its computers,

thanks for ur information,

so i have put a new router.