4 Adjust /etc/hosts

Next we edit /etc/hosts. Make it look like this:

vi /etc/hosts

# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               localhost.localdomain localhost
192.168.0.100           server1.example.com server1
::1             localhost6.localdomain6 localhost6

It is important that you add a line for server1.example.com and remove server1.example.com and server1 from the 127.0.0.1 line.

5 Configure Additional IP Addresses

(This section is totally optional. It just shows how to add additional IP addresses to your network interface eth0 if you need more than one IP address. If you're fine with one IP address, you can skip this section.)

Let's assume our network interface is eth0. Then there is a file /etc/sysconfig/network-scripts/ifcfg-eth0 which looks like this:

cat /etc/sysconfig/network-scripts/ifcfg-eth0

# Advanced Micro Devices [AMD] 79c970 [PCnet32 LANCE]
DEVICE=eth0
BOOTPROTO=static
BROADCAST=192.168.0.255
HWADDR=00:0C:29:08:8F:8E
IPADDR=192.168.0.100
NETMASK=255.255.255.0
NETWORK=192.168.0.0
ONBOOT=yes

Now we want to create the virtual interface eth0:0 with the IP address 192.168.0.101. All we have to do is to create the file /etc/sysconfig/network-scripts/ifcfg-eth0:0 which looks like this (we can leave out the HWADDR line as it is the same physical network card):

vi /etc/sysconfig/network-scripts/ifcfg-eth0:0

DEVICE=eth0:0
BOOTPROTO=static
BROADCAST=192.168.0.255
IPADDR=192.168.0.101
NETMASK=255.255.255.0
NETWORK=192.168.0.0
ONBOOT=yes

Afterwards we have to restart the network:

/etc/init.d/network restart

You might also want to adjust /etc/hosts after you have added new IP addresses, although this is not necessary.

Now run

ifconfig

You should now see your new IP address in the output:

[root@server1 ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0C:29:08:8F:8E
          inet addr:192.168.0.100  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe08:8f8e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:327 errors:0 dropped:0 overruns:0 frame:0
          TX packets:337 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:28434 (27.7 KiB)  TX bytes:56947 (55.6 KiB)
          Interrupt:17 Base address:0x1400

eth0:0    Link encap:Ethernet  HWaddr 00:0C:29:08:8F:8E
          inet addr:192.168.0.101  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:17 Base address:0x1400

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:560 (560.0 b)  TX bytes:560 (560.0 b)

[root@server1 ~]#

6 Configure The Firewall

I want to install ISPConfig at the end of this tutorial which comes with its own firewall. That's why I disable the default Fedora firewall now. Of course, you are free to leave it on and configure it to your needs (but then you shouldn't use any other firewall later on as it will most probably interfere with the Fedora firewall).

Run

system-config-securitylevel

Select Disabled and press OK.

To check that the firewall has really been disabled, you can run

iptables -L

afterwards. The output should look like this:

[root@server1 ~]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
[root@server1 ~]#

7 Disable SELinux

SELinux is a security extension of Fedora that should provide extended security. In my opinion you don't need it to configure a secure system, and it usually causes more problems than advantages (think of it after you have done a week of trouble-shooting because some service wasn't working as expected, and then you find out that everything was ok, only SELinux was causing the problem). Therefore I disable it (this is a must if you want to install ISPConfig later on).

Edit /etc/selinux/config and set SELINUX=disabled:

vi /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#       enforcing - SELinux security policy is enforced.
#       permissive - SELinux prints warnings instead of enforcing.
#       disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
#       targeted - Targeted processes are protected,
#       mls - Multi Level Security protection.
SELINUXTYPE=targeted
# SETLOCALDEFS= Check local definition changes
SETLOCALDEFS=0

Afterwards we must reboot the system:

shutdown -r now

8 Install Some Software

First we import the GPG keys for software packages:

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*

Then we update our existing packages on the system:

yum update

Now we install some software packages that are needed later on:

yum install fetchmail wget bzip2 unzip zip nmap openssl lynx fileutils ncftp gcc gcc-c++