CentOS - Nov 2011 - ip command

Hi all,
I have this network:
10.1.20.0 - 10.1.23.0 /22
Broadcast 10.1.23.255

Say I have a machine with IP: 192.168.1.1
Now, I want to create virtual IP on it with ip command:

1. Is this ok?
ip addr add 10.1.22.100/22 dev eth0:1

2. Should I define the broadcast too in the above command?
If I don't define it, will the above command means the broadcast would
be 10.1.25.255?

Thank you.
Fajar.

> Hi all,
> I have this network:
> 10.1.20.0 - 10.1.23.0 /22
> Broadcast 10.1.23.255
>
> Say I have a machine with IP: 192.168.1.1
> Now, I want to create virtual IP on it with ip command:
>
> 1. Is this ok?
> ip addr add 10.1.22.100/22 dev eth0:1
>
> 2. Should I define the broadcast too in the above command?
> If I don't define it, will the above command means the broadcast would
> be 10.1.25.255?
By specifying /22 as the subnet mask, you're implicitly specifying the
broadcast address. You don't need to specify it, manually.

However, based on a CIDR notation of /22 (which is a subnet mask of
255.255.252.0), the broadcast will actually be 10.1.23.255.

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Fajar Priyanto writes:
> Hi all,
> I have this network:
> 10.1.20.0 - 10.1.23.0 /22
> Broadcast 10.1.23.255
> 
> Say I have a machine with IP: 192.168.1.1
> Now, I want to create virtual IP on it with ip command:
> 
> 1. Is this ok?
> ip addr add 10.1.22.100/22 dev eth0:1
ip a a 10.1.22.100/22 dev eth0

that will do
> 
> 2. Should I define the broadcast too in the above command?
> If I don't define it, will the above command means the broadcast would
> be 10.1.25.255?
you can skip the broadcast if you want

--
Nux!
www.nux.ro