General Discussion

Author

subnet

kumkum

2004-01-27, 9:31 pm

Hi,
I have a question about LAN.
When we build a LAN, we need to assign each hosts, and server in that LAN with IP address with the same subnet mask, right? If we don't do that, they won't be able to reach each other. I'd like to know why we can't have 2 or more different subnets in a LAN. I mean in a LAN without router. Is it related to classful and classless IP address? For example, when we type ping, we only specify the IP address without subnet mask, so the LAN must be assumed that all PC and server in that LAN must have the same subnet mask. Is that right or wrong? Could anyone please tell me? Thank you.

peterd

2004-01-28, 4:15 am

hi,

the subnet mask is either specified somewhere such as the IP settings on the PC that issues the ping, or the ping software assumes the subnet mask from teh IP address (class A - E).

I think you can have different address ranges on a LAN (not something I've ever tried to do!) but you'd need a router (or a PC with two network cards) to connect from one address range to the other.

Regards
Peter

HOOLIGAN

2004-01-28, 9:05 am

you can put different subnets on to a LAN,then by definition of a LAN you will have created two LANS, or as we have at work VLANS ( virtual LANS ) set up on switches.

I have never tried it but I cant see why you can't do this on a broadcast LAN its just the Hosts will only communicate with the machines on their own subnet. Unless you set up multi homed machines or a router like peterd suggests.

jarbob69

2004-01-30, 7:12 am

You can have as connect as many subnets to a hub as you want, but you have to have a router or other layer 3 device (e.g., switch with VLAN) to cross boundaries between subnets. Without that, only intra-subnet communication occurs, and if you're on a hub, you would have packet storms galore due to all the broadcasting.

Sponsored Links