[CentOS] CentOS 6 : Network Interface Naming

Mon Nov 25 22:08:25 UTC 2013
Kahlil Hodgson <kahlil.hodgson at dealmax.com.au>

/etc/udev/rules.d/70-persistent-net.rules is your friend

the device names defined in there are set nice and early during boot,
well before any ifcfg scripts


Kahlil (Kal) Hodgson                       GPG: C9A02289
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On 16 November 2013 10:12, SilverTip257 <silvertip257 at gmail.com> wrote:
> On Fri, Nov 15, 2013 at 2:33 PM, Scott Robbins <scottro at nyc.rr.com> wrote:
>> On Fri, Nov 15, 2013 at 01:50:18PM -0500, SilverTip257 wrote:
>> > Hello All,
>> >
>> > I have one CentOS 6 KVM virtualization server that I built around a year
>> > ago (best I can tell it was in October 2012) at which time I would have
>> > been installing 6.3 [0].  That particular install used the Consistent
>> > Network Device Naming [1] conventions (PCIe NICs are p1p1, p1p2).
>> This regression is a combo RedHat/Dell idea, IIRC.  That may be why it's
>> that way on a Dell machine.  On Fedora, which usually shows what new
>> regressions will be in RH, it's gotten harder to fix with each iteration.
>> To make it worse, at least on Fedora (and again, many of their ideas,
>> whether good or bad for servers, get into RedHat) has apparently now been
>> intertwined with systemd.  At first, one simply had to remove the
>> biosdevnames rpm to fix it.  Now, one has to do that, and also add, (in
>> Fedora, with grub2) net.ifnames=0 to the kernel line.  (Note that this was
>> for Fedora 19, not sure if they at least removed biosdevnames in F20).
> I'm not tied to wanting my network interfaces to be ethX.
> Once my servers are configured, I'm generally not changing anything, so for
> all it matters they could be called wan0, etc.
> I actually think some of the conventions are worthwhile (ex: em for
> embedded, pXpY for PCI cards - I've not seen any others on Fedora/CentOS).
>  I believe embedded NIC naming on Dell hw starts with em1 rather than em0
> which is odd (we start counting at zero!).
>> To make it even more of a mess, (again, this is judging from Fedora, which
>> is good to keep on hand to see what new decisions good and bad will be made
>> by RH), I think biosdevnames gave it one name and then the whole systemd
>> thing gave it another.  So, it would boot up as say p12p but in
>> /etc/sysconfig/network-scripts it would show up as ifcfg-p1p2p or something
>> like that. (I'm making these names up, but that was the general idea.)
> I did see something similar to this, I believe it was on a Fedora system I
> was using for testing ... I don't recall which release though.
> RHEL7 ought to have some "Easter eggs" for us. ;)
>> Some people consider it a good thing, especially when moving drives between
>> machines, but aside from it being something new, which isn't necessarily
>> improved, it breaks various working scripts.
>> Like you, I consider it a regression, but of course, that's only my
>> opinion, and many experienced folks disagree, thinking it's a good
>> thing--although I'm sure that even they would agree that they better figure
>> out if biosdevname or something else will be handling it so that it is at
>> least consistent.
> I'm not calling the biosdevname conventions a regression.
> But what I am calling a regression is all the flip flopping between the old
> convention and the new one, especially on two nearly identical hardware
> builds and OS builds for that matter.
>> Actually, I think (but am not sure, that in VMs, even Fedora will use the
>> eth0, eth1 system rather than the new naming scheme.  Not just KVM, but
>> also VirtualBox, VMware, and so on--that has been my experience with CentOS
>> VMs at least.
>> --
>> Scott Robbins
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>> ( 1B48 077D 66F6 9DB0 FDC2 A409 FA54 EB34 67D6 )
>> gpg --keyserver pgp.mit.edu --recv-keys EB3467D6
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> --
> ---~~.~~---
> Mike
> //  SilverTip257  //
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