I have tried to install CentOS 6 on an older system.  When I get to the
prompt screen for the hostname of the computer there is a configure network
button at the bottom of the screen which is non selectable.   After filling
in the hostname for the machine the configure network button is still
unelectable.  Without being able to select the button I continued and
completed the installation of the CentOS 6 on the system, but when done with
installation I have no internet connection.

I see the network connection icon in the upper right hand corner of the
status bar in Gnome, and when I right click edit connections, I see Auto
eth0 in the connections screen last used is never.  When I highlight it and
click edit I can see a MAC address listed.  in IPv4 and in IPv6 method is
set to Automatic (DHCP).  Connect Automatically box is checked  and it is
available to all users.  Still no internet connection

ifconfig gives the following info:

eth0

Link encap:Ethernet HWaddr: 00:13:20:BF:DA:56
inet addr:192.168.0.103 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe88::213:20ff:febf:da56/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:721 errors:0 dropped:0 overruns:0 frame:0
TX packets:222 errors:0 dropped:0 overruns:) carrier:0
collisions:0 txqueuelen:1000
RX bytes:59817 (58.4 KiB)  TX bytes:21873 (21.3 KiB)
Interrupt:16

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 Mertric:1
RX packets:12 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:720 (720.0 b) TX bytes:720 (720.0 b)

------------

resolve.conf has the following:

# Generated by NetworkManager
nameserver 192.168.0.1

(the IP address listed in resolve.conf is my router's gateway address)

There was no ifcfg-eth0 file created in /etc/sysconfig/netwroking/devices
 so I created one and put the following in it:

DEVICE=eth0
BOOTPROTO=none
HWADDR=00:13:20:BF:DA:56
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes
NETMASK=255.2555.255.0
IPADDR=192.168.0.10
GATEWAY=192.168.0.1

--------

after this I have brought eth0  down and back up using if down eth0 and ifup
eth0

I get an OK on the following:

Shutting down loopback interface:
Bringing up loopback interface:
Bringing up interface Auto_eth0:  Active connection state: activating
Active connection path: /org/freedesktop/NetwokManager/ActiveConnection/2
state: activated
Connection activated

Still no internet connection.  Please help, Thanks

-- 
James