[rhelv6-list] RHEL7 NIC naming convention

[Bryan J Smith]

On Thu, Feb 13, 2014 at 2:08 AM, Romu <huruomu at gmail.com> wrote:
> RHEL7 uses different names for NICs,
> in RHEL4/5/6 it's always eth0/1/2/3...,

This is incorrect.

RHEL6.1+ introduced [1a] [1b] the biosdevname option which lets the
firmware define how devices are named.  It can be disabled by not
installing the package "biosdevname" and/or by removing entries from,
or the file, "/etc/udev/rules.d/70-persistent-net.rules" or any
related file "/etc/udev/rules.d/*-biosdevname.rules".

In-a-nutshell ... a lot of PC OEMs were asking for this, and Dell
(among others) was behind it, to avoid enumeration or confusion
between Ethernet-on-Motherboard (em#) and PCI device ports (p#p#).
There are two of the most common naming conventions, but they are
ultimately left up to the OEMs.

-- bjs

[1a] https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-single/6.1_Release_Notes/index.html#idp95564240
[1b] https://access.redhat.com/site/articles/53579

> but in RHEL7 I've seen em1/2, ens3...  What is the rule here?  How can I
> know whether the NIC name will be em or ens?

The binary included with the package reads from firmware/memory to set
the names.  There are several guides out there on finding the
appropriate identification for a board.


--
Bryan J Smith - UCF '97 Engr - http://www.linkedin.com/in/bjsmith
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