[libvirt-users] virsh and disable interface

[Laine Stump]

On 04/28/2016 06:32 PM, Mohsen Pahlevanzadeh wrote:
> According to 
> http://wiki.libvirt.org/page/Networking#Debian.2FUbuntu_Bridging
> May be I have to do "ifdown eth0"
> How can I define, edit or other task live? 

I don't use Ubuntu or debian, so I can't say if this works properly for 
them, but on RHEL-based distros (those that use ifcfg files in 
/etc/sysconfig/network-scripts) you can make all of the modifications to 
the config while the ethernet interface is still up, then run "ifup 
eth0; ifup br0" on a single commandline (or maybe it's "ifup br0; ifup 
eth0", I forget the proper order) - the old config of eth0 (which has an 
IP address) will be replaced with the new (which doesn't have an IP 
address and is attached to br0) and the bridge will be brought up. 
Although there will be a short loss of network connectivity, it will 
last for only a very small fraction of a second, so won't be noticed by 
any applications.