Red Hat Networking problem

This happened recently to me when the system was upgraded and now is
happening again with a new system.

Can't connect to the local network. (I can ping my local server)

cabling looks Ok, eth0 settings look fine (valid ID, etc) a default
route has been created, network software has been restarted and server
has been rebooted.

Someone fixed this once and I'm not sure how.

Any good web sites where Linux Networking problems (and
troubleshooting docs) might exist?

tx

On Feb 7, 1:36 pm, "Petyr David" <phyn...@gmail.com> wrote:
> This happened recently to me when the system was upgraded and now is
> happening again with a new system.
>
> Can't connect to the local network. (I can ping my local server)
>
> cabling looks Ok, eth0 settings look fine (valid ID, etc) a default
> route has been created, network software has been restarted and server
> has been rebooted.
>
> Someone fixed this once and I'm not sure how.
>
> Any good web sites where Linux Networking problems (and
> troubleshooting docs) might exist?
>
> tx

Use 'lspci | grep Eth' to see if your network adapter is still being
seen on the pci bus.

Use 'lsmod' to see if your network adapter's driver module is being
loaded

Look through '/etc/sysconfig/hwconf' to see which 'ethX' is your
network adapter.

Do an 'ifconfig ethX' to see if your interface is coming up. If it
is...

Try using 'ethtool -t' command, and 'netstat -i'
When using netstat -i, look for received packets, as this will tell
you if the interface is even getting anything from your network.

If the ethX interface is not coming up...
Do a 'tail -f /var/log/messages' in one console, and remove 'modprobe -
r drivername' and re-add 'modprobe drivername' the module your network
adapter uses in another console. Look at the messages that are
displayed while you re-add the driver.

If everything looks good above, then exec 'arping X.X.X.X' on an
address that you know is alive on your local network.' You should get
1 reply with the MAC address of the interface you targeted.

Try doing an 'arping X.X.X.X' from another machine, to the address
you're trying to set on your problematic nic. If things are working
right, you'll get 1 reply from the MAC that is your problematic nic.
If you get more than 1 reply, or a different MAC, there may be another
interface out there that has the same IP address as your problematic
nic.

Hope this helps.

peace,

-Anthony Altemara

On Feb 8, 4:44 pm, "AnthonyM" <anthony.altem...@gmail.com> wrote:
> On Feb 7, 1:36 pm, "Petyr David" <phyn...@gmail.com> wrote:
>
> > This happened recently to me when the system was upgraded and now is
> > happening again with a new system.
>
> > Can't connect to the local network. (I can ping my local server)
>
> > cabling looks Ok, eth0 settings look fine (valid ID, etc) a default
> > route has been created, network software has been restarted and server
> > has been rebooted.
>
> > Someone fixed this once and I'm not sure how.
>
> > Any good web sites where Linux Networking problems (and
> > troubleshooting docs) might exist?
>
> > tx
>
> Use 'lspci | grep Eth' to see if your network adapter is still being
> seen on the pci bus.
>
> Use 'lsmod' to see if your network adapter's driver module is being
> loaded
>
> Look through '/etc/sysconfig/hwconf' to see which 'ethX' is your
> network adapter.
>
> Do an 'ifconfig ethX' to see if your interface is coming up. If it
> is...
>
> Try using 'ethtool -t' command, and 'netstat -i'
> When using netstat -i, look for received packets, as this will tell
> you if the interface is even getting anything from your network.
>
> If the ethX interface is not coming up...
> Do a 'tail -f /var/log/messages' in one console, and remove 'modprobe -
> r drivername' and re-add 'modprobe drivername' the module your network
> adapter uses in another console. Look at the messages that are
> displayed while you re-add the driver.
>
> If everything looks good above, then exec 'arping X.X.X.X' on an
> address that you know is alive on your local network.' You should get
> 1 reply with the MAC address of the interface you targeted.
>
> Try doing an 'arping X.X.X.X' from another machine, to the address
> you're trying to set on your problematic nic. If things are working
> right, you'll get 1 reply from the MAC that is your problematic nic.
> If you get more than 1 reply, or a different MAC, there may be another
> interface out there that has the same IP address as your problematic
> nic.
>
> Hope this helps.
>
> peace,
>
> -Anthony Altemara

Uh ... thanks for the great help, which I have subsequently used. My
problem: I wasn't plugged into the default ehter card. DOH!