linux

User / Group Disk Quotas A three Step Guide

A disk quota is a limit set by a system administrator that restricts certain aspects of file system usage on modern operating systems. "Wikipedia"

Requirements : Quota Package

Where to get it : Quota package is generally available in majority of Linux Distros but still if your distro doesn't provide you with Quota compile it from http://sourceforge.net/projects/linuxquota/ :)

Step 1) Installation :

a) openSUSE : yast -i quota

b) Ubuntu : sudo apt-get install quota

c) Fedora : yum install quota

d) Others : Use rpm or compile if not available

 

Step 2) Enable Disk Quota

Disk quota is generally applied on a user or a set of users to its recommended to enable Disk Quota on your Home partition dont enable quota on the root partition unless you are under the expert category

How to Masquerade (ICS) in Linux

Its very simple to masquerade in linux with few lines of iptables and ip_forward commands.

Assumptions : Your Linux box has 2 NIC's one connected to internet (eth0) other connected to local network (eth1 IP 192.168.0.10)

first of all you have to flush and delete existing firewall rules which are there by default in linux .

so flush rules by typing the following in terminal

iptables -F
iptables -t nat -F
iptables -t mangle -F

now delete the chains by using

iptables -X
iptables -t nat -X
iptables -t mangle -X

now its time to save iptables so type

service iptables save
service iptables restart

now all rules and chains will clear !

check it by /etc/sysconfig/iptables which has all defaults rules set to accept.

now open /etc/rc.d/rc.local

and insert the following line

Configuring DHCP Server on Ubuntu

Ubuntu works the apt-get way and hence makes it easy to install packages on it for confuguring Ubuntu as a DHCP server install the server software using the following command

$ sudo apt-get install dhcp3-server

this would install the required packages

after the package is installed backup the default configuration files using the following

$ sudo cp /etc/default/dhcp3-server dhcp3-server.back

dhcp3-server is a file where you specify the interface DHCP should server (wlan0 in mycase)

edit the file using

$ sudo vim /etc/default/dhcp3-server

change

INTERFACES=””

to

INTERFACES=”wlan0”

(wlan0 might be eth0 or eth1 in your case)

save and close the file

only one more file editing is required now create a backup for mail dhcpd.conf using

$ sudo cp /etc/dhcp3/dhcpd.conf /etc/dhcp3/dhcpd.conf.back

edit the file using