Fedora Core Linux Network Management file and config

   Below show list of some network management tools, network files setup and network files configuration files in Fedora Core Linux operating system.

Network file example

The network file contain the information or setting of system network configuration.  The network file usually located under /etc/sysconfig/network directory.

[root@fedora ~]# less /etc/sysconfig/network

NETWORKING=yes/no # Presence of network use

NETWORKING_IPV6=yes/no # Presence of Ipv6 network use

HOSTNAME=RedHatA # host name

GATEWAY=193.0.0.1 # Specification of default gateway

NISDOMAIN=dimainnameA # Specification of NIS domain name

Hosts file example

To get more information on hosts (/etc/hosts)

[root@fedora ~]# man hosts

Example of hosts file.

[root@fedora ~]# less /etc/hosts

# Do not remove the following line, or various programs

# that require network functionality will fail.

127.0.0.1 localhost.localdomain localhost

Explanations: IP address,hostname,alias(Alias of hostname)

Type of network interface

1. lo (local loop back interface)

lo is recognized only internally of the computer.

Lo IP adress is 127.0.0.1.

2. Ethernet card (ethernet)

eth0,eth1,eth2,,,,

Edit network interface file

The network interface file or scripts usually located under /etc/sysconfig/nework-scripts/ directory.

1. /etc/sysconfig/nework-scripts/ifcfg-lo

2. /etc/sysconfig/nework-scripts/ifcfg-eth0

[root@fedora ~]# /etc/sysconfig/nework-scripts/ifcfg-lo

DEVICE=lo

IPADDR=127.0.0.1

NETMASK=255.0.0.0

NETWORK=127.0.0.0

BROADCAST=127.255.255.255

ONBOOT=yes # To make sure that the start and stop of these network service automatically control by the scripts.

NAME=loopback

[root@fedora ~]# less /etc/sysconfig/nework-scripts/ifcfg-eth0

DEVICE="eth0"

BOOTPROTO="none"

IPADDR="10.10.0.235"

NETMASK="255.255.0.0"

ONBOOT="yes"

Using 'ifconfig' command to state the properties of network interface

The example below show the output of the 'ifconfig' command that display the properties of Ethernet card (eth0) and the local loopback address (lo).

[root@fedora ~]# ifconfig

eth0 Link encap:Ethernet HWaddr 00:50:FC:1E:36:A5

inet addr:10.10.0.235 Bcast:10.10.255.255 Mask:255.255.0.0

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:30315 errors:7 dropped:0 overruns:0 frame:0

TX packets:708 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:100

RX bytes:2398091 (2.2 Mb) TX bytes:117446 (114.6 Kb)

Interrupt:5 Base address:0x9000

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:36 errors:0 dropped:0 overruns:0 frame:0

TX packets:36 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:2868 (2.8 Kb) TX bytes:2868 (2.8 Kb)

(Explanation)

MTU(maximum Transfer Unit)

The maximum value of size of packet which can be forwarded

RX packets: Received number of packets

TX packets: Transmitted number of packets

collisions: Frequency by which collision is caused

txqueuelen: Length of transmission cue

RX bytes: Received number of bytes

TX bytes: Transmitted number of bytes

Start and stop the network interface card on Linux Fedora Core

Using Linux ifconfig command to bring network interface card up and down.

[root@fedora ~]# ifconfig eth0 up

[root@fedora ~]# ifconfig eth0 down

Using Linux ifup and ifdown command to bring network interface card up and down.

[root@fedora ~]# ifup eth0

[root@fedora ~]# ifdown eth0

Using Linux service command  to bring network interface card up and down.

[root@fedora ~]# service network stop

[root@fedora ~]# service network start

Using network scrip (locate under /etc/rc.d/init.d/ directory) to start, stop, restart, reload and to display the network status.

[root@core init.d]# /etc/rc.d/init.d/network

Usage: /etc/rc.d/init.d/network {start|stop|restart|reload|status}

Display network status

[root@core init.d]# /etc/rc.d/init.d/network status

Configured devices:

lo eth0

Currently active devices:

lo eth0

To stop network interface

[root@fedora /]# /etc/rc.d/init.d/network stop

Shutting down interface eth0:     [ OK ]

Shutting down loopback interface: [ OK ]

To start the network inteface

[root@fedora /]# /etc/rc.d/init.d/network start

Bringing up loopback interface: [ OK ]

Bringing up interface eth0:     [ OK ]

To restart the network interface, shutting down the network interface and then bring the network interface up again.

[root@fedora /]# /etc/rc.d/init.d/network restart

Shutting down interface eth0:     [ OK ]

Shutting down loopback interface: [ OK ]

Bringing up loopback interface:   [ OK ]

Bringing up interface eth0:       [ OK ]

Display hostname and change to new host name

Display the host name on Linux Fedora Core.

[root@fedora ~]# hostname

fedora.hacking.com

Change host name using 'hostname' command

[root@fedora ~]# hostname core.hacking.com

[root@fedora ~]# hostname

core.hacking.com

Logout and login again to apply changes.

[root@core ~]# hostname

core.hacking.com

Setup / change the hostname manually

To setup the hostname manually on Linux Fedora Core machine, you need to edit two files: /etc/sysconfig/ network and /etc/ hosts.

1.  On the /etc/sysconfig/ network file, modify the hostname:

Configuration example on network file:

NETWORKING=yes

HOSTNAME=fedora.hacking.com

GATEWAY=10.7.0.1

2.  On the /etc/ hosts file, modify the hostname:

Configuration example on hosts file:

# Do not remove the following line, or various programs

# that require network functionality will fail.

127.0.0.1 fedora.hacking.com fedora localhost.localdomain localhost

Ping Host

The packet is transmitted, and it is confirmed whether the packet reaches host destination correctly.

Please push CTRL-C when the confirmation ends.

1.  The example of reaching packet to host.

[root@fedora ~]# ping 10.10.0.233

PING 10.10.0.233 (10.10.0.233) from 10.10.0.235 : 56(84) bytes of data.

Warning: time of day goes back, taking countermeasures.

64 bytes from 10.10.0.233: icmp_seq=0 ttl=128 time=216 usec

64 bytes from 10.10.0.233: icmp_seq=1 ttl=128 time=127 usec

64 bytes from 10.10.0.233: icmp_seq=2 ttl=128 time=137 usec

64 bytes from 10.10.0.233: icmp_seq=3 ttl=128 time=119 usec

64 bytes from 10.10.0.233: icmp_seq=4 ttl=128 time=143 usec

64 bytes from 10.10.0.233: icmp_seq=5 ttl=128 time=125 usec

64 bytes from 10.10.0.233: icmp_seq=6 ttl=128 time=137 usec

--- 10.10.0.233 ping statistics ---

7 packets transmitted, 7 packets received, 0% packet loss

round-trip min/avg/max/mdev = 0.119/0.143/0.216/0.032 ms

2.  The example of not reaching packet to host.

[root@fedora ~]# ping 10.10.0.239

PING 10.10.0.239 (10.10.0.239) from 10.10.0.235 : 56(84) bytes of data.

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

From 10.10.0.235: Destination Host Unreachable

--- 10.10.0.239 ping statistics ---

12 packets transmitted, 0 packets received, +9 errors, 100% packet loss

ARP Reference and change in ARP cache

The ARP cache is a correspondence table of the MAC address and Internet Protocol address obtained by ARP.

[root@fedora ~]# arp -a

? (10.10.0.1) at 00:01:30:33:6D:00 [ether] on eth0

? (10.10.0.233) at 00:50:FC:24:D3:8B [ether] on eth0

neat

Neat is a program for a network environmental setting which moves on x window system.

Neat is selected the menu, the program, the system, and the network setting on GNOME

and starts.

Network and Hosts file properties.

Below show the example of network and hosts file properties.

[root@fedora ~]# cat /etc/sysconfig/network

NETWORKING=yes

HOSTNAME=fedora.hacking.com

GATEWAY=10.7.0.1

[root@fedora ~]# cat /etc/hosts

# Do not remove the following line, or various programs

# that require network functionality will fail.

127.0.0.1 fedora.hacking.com fedora localhost.localdomain localhost

[root@fedora ~]#

Keywords: Linux network management, network file, network configuration files, setup network, network config, Fedora Core, hosts file, sysconfig, arp, ping, change hostname, display hostname, ifconfig, network interface, configure network device.