Can't activate eth0 network connection

[McDougall, Marshall (FSH)]

>-----Original Message-----
>From: redhat-list-bounces at redhat.com 
>[mailto:redhat-list-bounces at redhat.com] On Behalf Of Dave Martini
>Sent: Monday, December 04, 2006 11:30 AM
>To: redhat-list at redhat.com
>Subject: Can't activate eth0 network connection
>
>I have an HP Proliant DL385 with RHEL 4.0 ES on it.
>
>I can't get the network device to activate to where I can ping the 
>machine or ping other machines from it.
>
>I noticed when I run ifconfig it says
>
>UP BROADCAST MULTICAST  MTU:1500  Metric:1
>
>but it doesn't have the word RUNNING in the output like it does on my 
>SunFire X4200 which does have an active network connection and looks 
>like this
>
>UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>
>Shouldn't it say RUNNING?
>
>I also noticed when running ethtool eth0 that it says
>Link detected: no
>
>I've verified that the network cable is good because I 
>switched it from 
>my SunFire which is working and which is connected to the same 
>gigabit hub.
>
>I ran the netconfig utility on the HP and entered the IP address and 
>netmask and nameserver and default gateway and DNS info. I have the 
>machines DNS name registered with my local DNS servers. My 
>/etc/nsswitch.conf file has the word files then dns for the hosts line.
>
>Is there something special on the HP I need to do to activate the 
>network interface? This machine has two nic connectors on the back 
>labeled 1 and 2. I have the cable plugged into 1 and on the front it 
>shows that there is a network link because the green light is on.
>
>THank you.
>Dave Martini
>LLNL
>
>-- 
>redhat-list mailing list
>unsubscribe mailto:redhat-list-request at redhat.com?subject=unsubscribe
>https://www.redhat.com/mailman/listinfo/redhat-list
>

What else does ifconfig tell you/us? (ip, mask, etc)
Do you have SELinux enabled?  If yes, disable it and test again.
Have you turned off your firewall. Same deal as SEL.
Have you tried "service network start/restart"
Have you set your speed/duplex to match that of the port on the switch?
Can you ping 127.0.0.1?

These are all the first things I look at when faced with network issues.
HTH.

Regards, Marshall