ifcfg-ethX voodoo for a second IP on the same interface

[Tommy Pham]

On Fri, Apr 20, 2012 at 10:30 PM, Tommy Pham <tommyhp2 at gmail.com> wrote:
> On Fri, Apr 20, 2012 at 10:05 PM, Ed Greshko <Ed.Greshko at greshko.com> wrote:
>> On 04/21/2012 12:55 PM, Tommy Pham wrote:
>>> On Fri, Apr 20, 2012 at 9:34 PM, Ed Greshko <Ed.Greshko at greshko.com> wrote:
>>>> On 04/21/2012 11:20 AM, Sam Varshavchik wrote:
>>>>> For testing purposes I need to add a second IP address to eth0.
>>>>>
>>>>> eth0 is managed by NetworkManager, and uses dhcp.
>>>>>
>>>>> I know that if I get rid of NetworkManager and put static IP addresses in
>>>>> ifcfg-eth0, I can also sprinkle some magic dust into ifcfg-eth0:1, and have the
>>>>> second IP address come up together with the first one.
>>>>>
>>>>> This does not seem to work with a NetworkManager-managed DHCP-based interface.
>>>>>
>>>>> Basically, is there some voodoo I can throw in a file somewhere that would perform
>>>>> the equivalent of:
>>>>>
>>>>> ip addr add 192.168.0.5 dev eth0 label eth0:1
>>>>>
>>>>> when eth0 comes up via DHCP, by NetworkManager?
>>>>>
>>>> Well.....  I think you can only do this with static IP addresses....
>>>>
>>>> But, all you have to do is modify /etc/sysconfig/network-scripts/ifcfg-whatever  to have
>>>>
>>>> IPADDR0=192.168.0.225
>>>> IPADDR1=192.168.0.226
>>>>
>>>> for example....
>>>>
>>>> Then you'd see...
>>>>
>>>> 2: p2p1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
>>>>    link/ether 08:00:27:36:bf:b0 brd ff:ff:ff:ff:ff:ff
>>>>    inet 192.168.0.225/24 brd 192.168.0.255 scope global p2p1
>>>>    inet 192.168.0.226/24 brd 192.168.0.255 scope global secondary p2p1
>>>>    inet6 fe80::a00:27ff:fe36:bfb0/64 scope link
>>>>       valid_lft forever preferred_lft foreve
>>>>
>>>>
>>>>
>>>> --
>>>> Never be afraid to laugh at yourself, after all, you could be missing out on the joke
>>>> of the century. -- Dame Edna Everage
>>> Then the documentation [1] is either wrong or did I completely read it wrong?
>>>
>>>
>>> [1] http://docs.fedoraproject.org/en-US/Fedora/16/html/System_Administrators_Guide/s2-networkscripts-interfaces-alias.html
>>
>> I didn't read the documentation....  :-)
>>
>> I think that method is how to do it when NetworkManager isn't being used.  What I was
>> describing was if you were using NetworkManager.
>>
>> One "downside" if using my method is that "ifconfig" won't show the second IP
>> address.  But since "Ifconfig" has been depreciated....  :-) :-)
>>
>> In any case, these configuration won't work when DHCP is desired.
>>
>> --
>> Never be afraid to laugh at yourself, after all, you could be missing out on the joke
>> of the century. -- Dame Edna Everage
>> --
>
> You're right about the doc and NetworkManager... I had to set it to no
> and bring down the service to make it work...  But then I'm using F17
> beta so maybe NM is broken???
>
> [root at fedora network-scripts]# ls ifcfg-p14*
> ifcfg-p14p1  ifcfg-p14p1:1
>
> [root at fedora network-scripts]# cat ifcfg-p14*
> UUID="d55f8a84-7d34-48a7-9183-de122db1d244"
> NM_CONTROLLED="no"
> HWADDR=**:**:**:**:**:**
> BOOTPROTO="dhcp"
> DEVICE="p14p1"
> ONBOOT="yes"
>
> #UUID="d55f8a84-7d34-48a7-9183-de122db1d244"
> NM_CONTROLLED="no"
> BOOTPROTO="none"
> DEVICE="p14p1:1"
> ONBOOT="yes"
> USERCTL=yes
> #TYPE=Ethernet
> IPADDR=192.168.0.11
> NETMASK=255.255.255.0
> #PREFIX=24
> #DEFROUTE=yes
> IPV4_FAILURE_FATAL=no
> #IPV6INIT=no
> NAME="System p14p1:1"
> UUID=3b279e0d-a2fe-82a3-d15e-6b6fa922d797
>
> p14p1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>        inet 192.168.0.241  netmask 255.255.255.0  broadcast 192.168.0.255
>        inet6 fe80::52e5:49ff:fe4e:e55a  prefixlen 64  scopeid 0x20<link>
>        ether **:**:**:**:**:**  txqueuelen 1000  (Ethernet)
>        RX packets 684  bytes 145345 (141.9 KiB)
>        RX errors 0  dropped 0  overruns 0  frame 0
>        TX packets 703  bytes 88987 (86.9 KiB)
>        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>        device interrupt 52  base 0x2000
>
> p14p1:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>        inet 192.168.0.11  netmask 255.255.255.0  broadcast 192.168.0.255
>        ether **:**:**:**:**:**  txqueuelen 1000  (Ethernet)
>        device interrupt 52  base 0x2000

but this last line from the doc...

"The easiest way to create alias and clone interface configuration
files is to use the graphical Network Administration Tool."

Perhaps network is not running and let NM take over?