Why can't I ping Gateway from centOS install?

what is the output for route -an

check if your default gateway is correct in their

when you ping what does it say ??
some time, its try to ping via different gateway ..

It seems that your network cable is not good, disconnected or on different VLAN.
If you have multiple ethernet ports, try another one.
Do you mean you can ping from Windows machine, connected to the same ethernet cable?

In addition to the above requests, what's the output of

mii-tool -v eth0

Starting from the top:
route -n Gives following:

Destination         Gateway          Genmask              Flags         Metric         Ref           Use Iface
192.168.1.0        0.0.0.0            255.255.255.0          U             0                 0               0  eth0
169.254.0.0        0.0.0.0            255.255.255.0          U             0                 0               0  eth0
0.0.0.0                192.168.1.1    0.0.0.0                     UG           0                 0               0 eth0

The cable is good because if I use it on an Windows box it works fine and pings out fine.


Output from mii-tool -v eth0:

eth0: negotiated 100baseTx-FD flow-control, link ok
    product info: vendor 00:aa:00, model 56 rev 0
    basic mode: autonegotiation enabled
    basic status: autonegotiation complete, link ok
    capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
    advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
    link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control

Thank you so much for your help so far. Anything you can add would be GREATLY appreciated.

> The cable is good because if I use it on an Windows box it works fine and pings out fine.

Just to be sure, do you mean the cable and the ethernet ports are the same?

Next question - what is your kernel version, NIC vendor/model and eth driver?

dmesg | grep eth
uname -r
lsmod

this is little bit of wired,

can windows pc ping this linux box ??

can linux box ping any windows pc ??

do you have Gateway address define in windows pc ??

OK, well I mean the cable is good for sure. I didn't not pull the NIC card as it is built into the motherboard, but I do have an Intel card somewhere I could pop in if I need to.

Other info:
dmesg | grep eth:

e1000: eth0: e1000_probe: Intel(R) PR/1000 Network Connection
ADDRCONF(NETDEV_UP): eth0: link is not ready
ADDRCONF(NETDEV_UP): eth0: link is not ready
ADDRCONF(NETDEV_UP): eth0: link is not ready
ADDRCONF(NETDEV_UP): eth0: link is not ready

uname -r:

2.6.18-92.e15

lsmod:

too much stuff, but e1000 had the number 155601 0 after it.

Are you thinking the NIC is bad? It was working when this box was setup as a Vista machine.

Just so you now it's an Intel Dual Xeon 3.4 with 4GIG ram and built in NIC card.

fosiul01:

To answer your questions:
1) No
2) No
3) Yes. Well, the Windows machines are getting DHCP from domain controller.

hi
i would not say your nic is bad, i never seen this problem but its likes there is a workwayround of this problem

have a look to this article, its big but should help you

http://linux.derkeiler.com/Mailing-Lists/Debian/2006-04/msg02353.html

> Are you thinking the NIC is bad?

May be. And I beleave that it was alive. If you can test in on Vista again and it would work, then it's OK :-)
Intel 1000 drivers are quite stable and theirs NICs too.

> ADDRCONF(NETDEV_UP): eth0: link is not ready

Here is a problem. Just for sure please change your cable. I know there are cables with intermittent problems. Also the PORT on your hub/switch may be dead or working unstable (if possible, connect it to another port and reset switch).
That's most probably a physical problem, change components one-by one and find what is failed.

The thing is, that mii-tool is reporting

eth0: negotiated 100baseTx-FD flow-control, link ok

Which indicates the link has auto-negotiated with the switch and set the interface to 100Mb full duplex.  It wouldn't be able to do that if it had no connection.

Couple more things to try

Do a

ping -s 192.168.1.1

and in another terminal session, do

tcpdump dst 192.168.1.1

and see what it reports

Tintin;

Did what you said. Session 1 is pinging away at 192.168.1.1 and session 2 is flashing at the tcpdump prompt not reporting anything. Says it's listen on eth0, link-type EN10MB bt nothing is happening. It's been about 10 minutes.

OK, try doing

tcpdump

to see if there are any packets whatsoever on the network.

Also, what messages do you get back from ping?

Nope, nothing. :) I wish I knew what I was doing wrong. I feel like I'm wasting everyone's time on something stupid. I do very much appreciate the help.

Message back from ping is "destination host unreachable"

New information:

I installed a new Intel NIC card EXACTLY like the one built into the mother board. I get the exact same messages to all of the questions about except as eth1. I'm thinking it's got to be something driver related. Any thoughts would be appreciated.

> I had to reset the BIOS to factory "fail safe" settings and then the NIC worked fine

Very interesting... I recommend you to mark your post as self-answered, so it will be PAQed and come to knowledge base.

It whould be even better if you protocol here your motherboard/BIOS version and kernel verstion :-)