Interesting observation on fedup to fc18

Bill Davidsen davidsen at
Thu Mar 21 00:51:19 UTC 2013

After upgrading via fedup to fc18, I noted with surprise that the NIC was 
renamed from eth0 to p17xx. Since I had se the system biosnames to return ethN 
on all single NIC desktops, I expected that to be carried forward in an upgrade. 
As you would expect all the inst scripts failed and the system never came up.

In case it's useful to someone else who is unhappy with upgrades breaking things 
they need not, here's my fix:
   # because every upgrade of Fedora changes the name of the damn default NIC,
   # get it from the system rather than using what you want.
   NIC=$(ip route | awk '/default/{print $5}')

And to get the IP on the NIC (I run DHCP to set the IP, reverse DNS to get the 
"real" machine name.
   # save the IP
   eth0IP=$(ifconfig ${NIC} | awk '/^ *inet /{print $2}' | sed 's/.*://')

Note that the IP determination works for old versions of ifconfig which return a 
different information format.

Hope this helps someone.

Bill Davidsen <davidsen at>
   We are not out of the woods yet, but we know the direction and have
taken the first step. The steps are many, but finite in number, and if
we persevere we will reach our destination.  -me, 2010

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