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Block an IP for a subnet by IPtables

Hi
I am looking to block an incomming IP for all the subnet in lab area. only single Ip should be access to this incomming IP.

Block IP=10.20.50.xx
Subnet=10.30.40.xx

can anyone explain how to do this by linux Iptables?

man ipcalc
man iptables

Search engine.

Its didn't help me what i was expecting. Ip calculating is different from Ip blocking.

Anyone has the comment on this?

Quote:

Originally Posted by boby.kumar (Post 5160324)

Its didn't help me what i was expecting. Ip calculating is different from Ip blocking.

Anyone has the comment on this?

That's funny, because it helped me set over 400 iptable bans on several of my own hosts.

Code:

ipcalc 10.20.50.00

Address:  10.20.50.0          

Netmask:  255.255.255.0 = 24  

Wildcard:  0.0.0.255            

=>

Network:  10.20.50.0/24        

HostMin:  10.20.50.1          

HostMax:  10.20.50.254        

Broadcast: 10.20.50.255        

Hosts/Net: 254                  Class A, Private Internet

Sooooooo, to block all 10.20.50.xx hosts, you would run:

Code:

for i in 10.20.50.0/24 ; do iptables -I INPUT -s $i -j DROP ; done

Unless I missed my daily dosage of caffeine, that should get you started.

Sorry for delayed responses.
My query is different rather below answered.
for i in 10.20.50.0/24 ; do iptables -I INPUT -s $i -j DROP ; done

My network(subnet) should be blocked to accessing the incomming rather than blocking the incommings.

AnYone have any comment now?