[SOLVED] can't set the IP of veth0

gnourt · 09-13-2018, 03:46 AM

I am trying to set IP for virtual Ethernet devices as below:

root@vxq:~# ip netn add net_ns0
root@vxq:~# ip netns exec net_ns0 ip link add veth0 type veth peer name veth1
root@vxq:~# ip netns exec net_ns0 ifconfig veth0 192.168.0.2/24
ifconfig: bad address '192.168.0.2/24'
root@vxq:~#

It appeared an error "bad address".
But I replaced "192.168.0.2/24" by "192.168.0.2 netmask 255.255.255.0". It was ok.

I think they're the same meaning.
I don't know why? Could you please explain me about this issue?

berndbausch · 09-13-2018, 04:29 AM

I am not sure, but I guess that ifconfig simply doesn’t support the CIDR format.

Since you use ip otherwise, why not for setting the address? For example:

Code:

ip a add 192.168.0.2/24 dev veth0

gnourt · 09-13-2018, 06:19 AM

Thank you for your answer!
Do you know how to check the ifconfig support CIDR format or not?

berndbausch · 09-13-2018, 02:03 PM

Quote:

Originally Posted by gnourt

Do you know how to check the ifconfig support CIDR format or not?

The man page states:

Synopsis
ifconfig [interface]
ifconfig interface [aftype] options | address ...
(...)
address
The IP address to be assigned to this interface.

It says IP address, not CIDR.