[CentOS] A question about 7

Wed Jan 15 19:09:50 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Wed, Jan 15, 2014 at 12:47 PM,  <m.roth at 5-cent.us> wrote:
>
>>>>> The problem is when you clone a disk and ship it to a location with
>>>>> 'hands-on' support that doesn't know linux to install in a new chassis
>>>>> that will arrive there at the same time.   Somehow you have to get
>>>>> someone to put the 4 network cables in the right NICs before anything
>>>>> can connect.   With things tied to MAC addresses that you don't know
>>>>> ahead of time, nothing will work.
> <snip>
>>>> We have to go through contortions
>>>> plugging on cable in at a time, doing an 'ifconfig up' and checking
>>>> which interface shows link up.   And the people  doing that part wish
>>>> we used more windows instead of Linux.
>>>
>>> ifconfig up? Not ethtool eth?
>>
>> You have to do both.  Link won't come up until you ifconfig up the
>> device - which of course is difficult when you don't know its name...
>
> I don't think so - pretty sure I was just using ethtool eth? the other
> week, to try to figure out the name of the port that I'd plugged the patch
> cord into. I *know* that the ones with nothing in them weren't up (and
> yes, obviously, I was at the console).

Maybe something else had already probed them.  I'm pretty sure that if
you bring up a system where all of the udev rules and ifcfg- files
have the wrong MAC addresses, none of the links will come up.    With
CentOS5 you could use mii-tool to enumerate the interfaces and show
link.   I think the best I've found with 6 is to use 'ip link ls' to
show the names, then one at a time 'ifconfig up' each name and then
use ethtool  to check for link.     All very awkward to describe to a
windows admin over the phone.

-- 
   Les Mikesell
      lesmikesell at gmail.com