NIC device detection/management

Scenarios

This applies to IPBRICK v6.0 on the following known situations:

• Hardware configuration with removed NICs that are not automatically cleared.
• IPBRICK installation that was migrated from one server to another (HDD moved from machine A to machine B).

In these scenarios the NIC information may be incorrect, in order to correct this you will need to execute the procedure bellow.

How to diagnose

Identify the number of NICs configured in the machine (physical or virtual). Identify the number of NICs detected/shown in the operating system (OS). In the OS, NICs are reported sequently as:

1. eth0
2. eth1
3. eth2
4. eth3
5. ....

In order to check the information on the OS you can execute as root:

ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 10:1f:74:e4:fe:c4  
          inet addr:87.196.239.131  Mask:255.255.255.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
...
#ETH0 is OK.

If the number of physical NICs doesn't match the number of OS detected NICs. Or if your OS can't find/provide information on a lower OS can't provide information on "lower" NICs.

ifconfig eth0
#eth0: error fetching interface information: Device not found
#ETH0 is NOT OK.

Context - UDEV - IPBRICK v6.0

In IPBrick version 6.0 after first boot, the following file is filled with information about the network interface cards (NIC) that exist in the server:

/etc/udev/rules.d/70-persistent-net.rules

This file is updated with a new record every time a new NIC is detected at boot time, meanwhile removed NICs are not automatically cleared from this file. So if you clear this file it will be automatically updated on the next boot.

Solution

To correct the udec NIC information file, proceed as follows:

#at the local console command line, login as root user and execute
cd /etc/udev/rules.d
rm 70-persistent-net.rules
touch 70-persistent-net.rules
reboot

The server will reboot and rebuild from scratch this file with the current NIC configuration.

NOTE: this procedure is to be executed at the local console, so you will need physical access to the server machine, or in virtual environment you will need access to the virtual machine console. Do not execute this procedure remotely because you may loose server network connectivity and so loose network remote access.

Advanced Network - BOND, BRIDGE

These advanced network configurations need aditional atention at the IPBRICK web interface.