Network Configuration 1

[BikerGal]

How do I decide what the network and broadcast fields should be in the installation of Red hat 7.3??

thanks a lot

 

[marsd]

Are you attached to a network?
If not then any private range should be fine.
192.168.1.23 255.255.255.0

 

[dankelt]

Don't the Network and Broadcast fields fill in automatically when you specify an IP address and subnet mask?

here is an example using a class C subnet:
IP address: 192.168.0.1
Subnet Mask: 255.255.255.0
Network: 192.168.0.0
Broadcast: 192.168.0.255

 

[fluid11]

That all depends on the subnet mask. Generally, you can follow this...

Class A - 255.0.0.0 - first octet is between 1-126
Class B - 255.255.0.0 - first octet is between 128-191
Class C - 255.255.255.0 - first octect is between 192-223

The above subnet masks are true if you aren't using a custom subnet mask, which you most likely aren't.

The broadcast address for the above masks is very simple to determine. Just take all the 0's and make them 255, and the 255's are replaced by your network ID. For example...

Network ID - 192.168.1.0
Subnet Mask - 255.255.255.0
Broadcast - 192.168.1.255

To be on the above network, you must have a IP address of 192.168.1.x, where x can be any number between 1 and 254.

Of course, this all changes with IPv6, but thats another story....


ChrisP

 

[BikerGal]

thanks a lot for all your help. My IP is 143.47.76.181. My subnet mask is 255.255.252.0. I was told that the reason for the .252 was because of the x.x.76.x format of the ip address. How do I work out then what the network and broadcast is? Will Linux be able to work this out for itself or do I need to alter it???

thanks again your information is very clear and easy to understand it can be hard to find this information.
P.S. can anyone recomend any good books that could help me I have also to set the machine up as an anomyous ftp server.

thanks,
Grainne

 

[dankelt]

Your Network number would be 143.47.76.0
Your Broadcast Address would be 143.47.79.255

To calculate this, first convert your ip address and subnet mask into binary.
To get the network number, you would do a Binary AND of the IP address and Subnet mask.

ip address: 10001111.00101111.01001100.10110101
snet mask: 11111111.11111111.11111100.00000000
_________________________________________________AND
ntwrk addr: 10001111.00101111.01001100.00000000


To get the Broadcast Address you would do and XOR of the inverted subnet mask with the network address.

network addr: 10001111.00101111.01001100.00000000
inverted smask: 00000000.00000000.00000011.11111111
___________________________________________________XOR
broadcast addr: 10001111.00101111.01001111.11111111