Block an IP address with null routes or with iptables on a Linux.

You can drop as IP address using the iptables command:

iptables -A INPUT -s -j DROP
iptables -A OUTPUT -d -j DROP

However, you can use route or ip command to a null route unwanted traffic. A null route is a network route or kernel routing table entry that goes nowhere.

route add gw lo

or reject 😉

route add -host reject

Also we can drop entire subnet

route add -net gw lo

To delete an IP address or entire subnet from a null route use the following command:

route del gw lo


route del -net gw lo

Can’t delete files/folders on a NSS volume.

While deleting files/folders on the NSS volume on an OES11 server as root user via shell. Let’s say test1.doc and the following error will occur:

“rm: cannot remove `test1.doc’: Permission denied” or “S-1-1-0-1 on a Windows machine.”

You will get that error if you have flagged the file with NSS flag “Delete Inhibit” or “Rename Inhibit”. Clear those flags out and it should also be possible to delete the file directly from a Linux console. Use this command:

root# attrib -r -c all foldername