?
Solved

Identify and enable second NIC card on a Ubuntu machine

Posted on 2016-08-01
7
Medium Priority
?
20 Views
Last Modified: 2016-08-02
I have a machine with Ubuntu 14.04 that my son set up for me to be a Plex server.  It has stopped connecting to the internet or even just the LAN. I verified the switch and cable by swapping in a CAT5 cable from another machine that sits right next to it and is working; no change.

I can see that this machine has a second NIC card port.  I have no documentation about the mother board.  I need an Ubuntu command to identify the MAC address of the second NIC card; I think when I have that I can set it up with the Network dialog box.
0
Comment
Question by:Mike Caldwell
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 2
7 Comments
 
LVL 7

Accepted Solution

by:
Phil Davidson earned 2000 total points
ID: 41738276
From the terminal, try this command:

ifconfig -a

Open in new window


This will list the NICs and reveal their MAC addresses.

The below commands should show an "operstate" field.  This should give a hint if a cable is physically connected:

grep "" eth0/*

grep "" eth1/*  

Open in new window


You might see what you can see in /sys/class/net/

You might want to try these commands:

sudo ethtool eth0 | grep Link

sudo ethtool eth1 | grep Link

Open in new window


The above was largely taken from this link.

If you look at both NICs that are physically connected to the server, are they flashing green, amber or solid red?  Those could help give clues.
0
 
LVL 1

Author Comment

by:Mike Caldwell
ID: 41738466
Thanks for pointing me in the right direction.  ifconfig showed only one ETH channel.  So I did open up the cabinet, get the MB model, and find the manual on line.  The "Integrated Peripherals" selection in the BIOS offered how to turn on the other ETH channel.  Did so, and Ubuntu really tried to get something out of it; it showed "Connecting" but never actually connected.  From the system diagram I have concluded that the PCI Experss bus must be shot, but to give this machine one more chance I'm going to pick up an outboard NIC card in the morning and see if that works.  If not, time to say goodbye to this MB.  Stay tuned for more!
0
 
LVL 35

Expert Comment

by:sarabande
ID: 41738544
the BIOS offered how to turn on the other ETH channel.

it is not very likely that both internal MB ethernet ports were defective. are they flashing red? you didn't answer to Phil's question.

you better check the connectivity again and try to Exchange the cable, plug the cable into another port of your switch or router and check the connectors. also unplug the router or switch from power, wait some time, and replug.

Sara
0
WordPress Tutorial 2: Terminology

An important part of learning any new piece of software is understanding the terminology it uses. Thankfully WordPress uses fairly simple names for everything that make it easy to start using the software.

 
LVL 1

Author Comment

by:Mike Caldwell
ID: 41739162
There were flashing yellow lights.  I swapped in the same CAT5 cable to the same switch that another unit nearby uses; no change.  I then plugged in the CAT5 coming from the router to the switch directly to this unit; no change.  Ubuntu would show that ETH2 was "connecting" but then timed out.  That would imply an external problem, but with the swapping that seems to not be the case.  So my theory is that there must be a common point from the CPU to the serial channels is bad; both are on the PCIe bus.  So for $15 I can get a NIC card and give it a try.  

If the NIC card does not work, and the externals are OK, I don't see what else I can do.
0
 
LVL 7

Expert Comment

by:Phil Davidson
ID: 41739915
Some motherboards have utilities that you can run on them.  Dell's hardware has such programs that test them without booting to an OS.  This can tell you if the motherboard is defective.
0
 
LVL 1

Author Comment

by:Mike Caldwell
ID: 41740005
Finally got ETH1 configured and ETH0 disabled.  Now reaching the internet.  Thanks to all.
0
 
LVL 1

Author Closing Comment

by:Mike Caldwell
ID: 41740043
Thanks Phil.  Didn't use all of this; the ifconfig got me going down the right path, plus I found the manual on line.
0

Featured Post

Create the perfect environment for any meeting

You might have a modern environment with all sorts of high-tech equipment, but what makes it worthwhile is how you seamlessly bring together the presentation with audio, video and lighting. The ATEN Control System provides integrated control and system automation.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article is in regards to the Cisco QSFP-4SFP10G-CU1M cables, which are designed to uplink/downlink 40GB ports to 10GB SFP ports. I recently experienced this and found very little configuration documentation on how these are supposed to be confi…
This article will show how Aten was able to supply easy management and control for Artear's video walls and wide range display configurations of their newsroom.
In this tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
Suggested Courses
Course of the Month9 days, 14 hours left to enroll

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question