UNIX for Dummies Questions & Answers

So after getting a Nagios plugin up and running that checks certain things including network interfaces, I get an error off the one box I built (as opposed to all of the others that were built by a former employee). The error complains of the "NIC logical group" failing.

All the boxes are HP DL380's with four physical NIC interfaces and an iLO port. For some reason the boxes not built by me all have ifcfg-eth configuration files for eth0 - eth5 (which would be six interfaces). While the machine I build only has eth0 - eth3 which corresponds to the four physical interfaces.

SO, I can assume from the error above, and the fact that eth4 and eth5 are not physical interfaces that they are some kind of logical interfaces configured but I'm not sure where to go from here with my investigation. I'm thinking there is some kind of link aggregation or bonding maybe going on, but not sure how to investigate this in Centos/Linux in general.

Any suggestions would be very much appreciated.

The presence of an ifcfg configuration file in /etc/sysconfig/network-scripts does not mean a physical interface, but rather a configuration for a connection with a device.

Look inside the other ifcfg-eth4 or ifcfg-eth5 in one of the servers that have them and that would tell you what their configuration is for.

All they give me is:

Code:

DEVICE="eth5"
BOOTPROTO="static"
HWADDR="hardware address"
NM_CONTROLLED="yes"
ONBOOT="no"
TYPE="Ethernet"
UUID="UUID"
IPADDR=IP Address
netmask=255.255.255.0

The only difference between eth4 and eth5 and the others (eth0-eth3)is that they are set to ONBOOT no, and their MAC addresses don't correspond to the actual physical MAC addresses (obviously).

---------- Post updated at 09:09 AM ---------- Previous update was at 08:57 AM ----------

In other words, its quite obvious that the former employee did something to configure these virtual interfaces for some reason, but how do I go about figuring out what?

Sorry I come from a Windows background, so outside of the normal everyday stuff a lot of this is still foreign to me in Linux.

Please use code tags instead of italics, [code]stuff[/code].

A network configuration file doesn't generally have the power to create a network device, just alter it. Take a closer look at eth4 and eth5 on those systems.

It's also possible that your systems have eth4/eth5, but aren't using them... If they're not "up", they wouldn't show in ifconfig. Try ifconfig -a to see if they appear.

As for what eth4/eth5 actually are, that's difficult to say without taking a look at them, examine them on one of the other systems, what are they connected to / doing, if anything?

Apologies, I will remember that in the future

These interfaces do show up in ifconfig, however none of them show as being up so quite frankly I'm not sure why they're there.

I was able to find the system-config-network-tui to create an eth4 and eth 5 on my test box, but when I do that it only gives me:

Code:

BOOTPROTO
ONBOOT
TYPE
IPADDR
NETMASK

So this does not duplicate what was done on the other boxes since they also have some sort of fake MAC addresses and UUID generated somehow

I mean in systems you didn't build. What are they doing there, if anything?