[CentOS] IP range

Thu Aug 2 14:12:40 UTC 2012
Nux! <nux at li.nux.ro>

On 02.08.2012 15:00, Birta Levente wrote:
> Hi all
>
> Can someone explain me this:
>
> ifcfg-eth0-range1:
> ONBOOT="yes"
> IPADDR_START="192.168.1.48"
> IPADDR_END="192.168.1.55"
> CLONENUM_START="1"
>
> Why Bcast is 192.168.1.51 and why Mask is 255.255.255.252 ?
>
> OS: Centos 6.3/64bit
>
>
> Thanks
>
> Levi
>
> # ifconfig
>
> eth0:1    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.48  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:2    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.49  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:3    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.50  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:4    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.51  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:5    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.52  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:6    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.53  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:7    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.54  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
> eth0:8    Link encap:Ethernet  HWaddr 00:9C:02:99:FA:00
>            inet addr:192.168.1.55  Bcast:192.168.1.51  
> Mask:255.255.255.252
>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            Interrupt:16 Memory:fbee0000-fbf00000
>
>
>
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You can (and are encouraged) to specify the NETMASK as well in that 
range file. I don't know why it uses that mask and broadcast; maybe it 
inherits them from other already configures interface?

-- 
Sent from the Delta quadrant using Borg technology!

Nux!
www.nux.ro