Problem configuring network

[Matthew Saltzman]

On Tue, 10 Apr 2007, Anne Wilson wrote:

> On Tuesday 10 April 2007 20:11, Matthew Saltzman wrote:
>> On Tue, 10 Apr 2007, Anne Wilson wrote:
>>> On Tuesday 10 April 2007, Tim wrote:
>>>> On Tue, 2007-04-10 at 11:08 -0700, Knute Johnson wrote:
>>>>> I've got an FC6 box that I'm having some trouble getting the network
>>>>> configured correctly.  I keep getting the error below when eth0 is
>>>>> started.  This happens on reboot or if I attempt to restart the
>>>>> network.
>>>>>     Networking works but I keep getting the error message.  Any ideas
>>>>> where I've gone wrong?
>>>>>
>>>>> [root at knute knute]# /sbin/service network restart
>>>>> Shutting down interface eth0:                              [  OK  ]
>>>>> Shutting down loopback interface:                          [  OK  ]
>>>>> SIOCGIFFLAGS: No such device
>>>>> Bringing up loopback interface:                            [  OK  ]
>>>>> Bringing up interface eth0:  sysfs class device: Permission denied
>>>>> Error, some other host already uses address 192.168.3.5.
>>>>>                                                             [FAILED]
>>>>
>>>> Taking the error notice at face value, you've got some other device on
>>>> the same network already using that address.  You can't do that, and it
>>>> checks when attempting to bring an interface on-line.  Change one of
>>>> them.
>>>
>>> Maybe something on the network grabbed the address via dhcp?
>>
>> Maybe Tim should be getting *his* IP via DHCP?
>>
> Maybe, but not necessarily.  It's possible to have both on one LAN.  On this
> LAN, for instance, we prefer to use static IP.  All our boxes have static
> addresses.  However one work laptop needs dhcp to access a company network.
> We tell the router to reserve the addresses that we use statically, and it
> issues addresses outside those to a dhcp box.

Sure, that's reasonable.  But a common cause of duplicate addresses is 
attempting to assign onesself an address manually from a range managed by 
a DHCP server.  My impression is that it is becoming more common to manage 
large networks with DHCP even when the machines are on the networks
permanently, just because the centralized management is simpler for the 
admin.

-- 
 		Matthew Saltzman

Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs