Month: February 2015

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 192.168.1.100 -j DROP
iptables -A OUTPUT -d 192.168.1.100 -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 192.168.1.100 gw 127.0.0.1 lo

or reject 😉

route add -host 192.168.1.100 reject

Also we can drop entire subnet 192.168.1.0/24

route add -net 192.168.1.0/24 gw 127.0.0.1 lo

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

route del 192.168.1.100 gw 127.0.0.1 lo

or

route del -net 192.168.1.0/24 gw 127.0.0.1 lo

or

route del -host 192.168.1.99 reject

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