Ran into an interesting issue that required me to put my newly learned Linux skills to the test!

After using Linux Academy for a few months to learn Linux, I ran into my first Linux tshooting scenario. I imported into AWS a copy of vCenter 5.5 Appliance. Now normally you should boot it up and see all the NICs right? Well for whatever reason this wasn’t the case, I only saw 1 NIC whereas the other two were just missing from my ifconfig output.

Now if this was a switch or Windows box I’d do a #show interfaces or a ncpa.cpl and see what NICs I see. Not the case here, all I had was a black console screen with some colored letters and a blinking cursor — here we go!

If you thought Google was your friend before, he’s about to become your BEST friend when it comes to learning/tshooting Python or Linux. One thing I really like transitioning from a vendor only product to an open source is that the whole world is open to helping out/posting scripts/fixing bugs/etc at a much quicker pace than the big companies do. And by doing a Google search I was able to find tons of free info people trying to solve this issue. Let this be yet another addition to that collection.

Anyhow, so first up — I had 3 NICs assigned to my vCenter Appliance box, but only 1 showed up for some reason. I went into the /etc/sysconfig/networking/devices and I only saw 1 NIC file there (ifcfg-eth0). That of course was one issue right there, I had to tell it it had more than 1 NIC and to also give it some config.

cd /etc/sysconfig/networking/devices
cp ifcfg-eth0 ifcfg-eth1
cp ifcfg-eth0 ifcfg-eth2

There, I just made copies from eth0 and created two more NICs. I also did a vi ifcfg-eth2 and gave it some static IP info. For example…

DEVICE=eth2
BOOTPROTO=static
STARTMODE=auto
TYPE=ethernet
USERCONTROL=no
IPADDR=192.168.1.1
NETMASK=255.255.255.0
BROADCAST=192.168.1.255

ESC > :wq! to save my file

Next I created a symbolic link to so when I do a network restart, it’ll know where to find these files in /network/. ┬áThis way, any changes done in the networking/devices dir gets replicated for me without needing to manage multiple copies of my NIC config. For that the command is…

ln -s /etc/sysconfig/networking/devices/ifcfg-eth1 /etc/sysconfig/network/ifcfg-eth1
ln -s /etc/sysconfig/networking/devices/ifcfg-eth2 /etc/sysconfig/network/ifcfg-eth2

Great, now restart the box or restart the network services via #service network restart. Now if you do a #ifconfig you’ll see the NICs! Hope that helps someone out there!

William Zambrano

William Zambrano

NYC networkers is run by William Zambrano, a passionate network engineer who has been in the IT industry for eight years who posts up blog articles, YouTube videos, and holds meetup.com events in the NYC area. He lives in Queens, New York and has consulted in various different companies in the NY area. Previously William worked as a Cisco Certified Systems Instructor (CCSI) but now currently works for Arista Networks serving as a Systems Engineer. William can be reached by email at willzambrano@gmail.com

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