[CentOS-virt] Why are bridges required?
lee at yun.yagibdah.de
Tue Jun 3 02:25:24 UTC 2014
all the descriptions of networking setups with VMs I`m seeing involve
bridges. The only use I see for bridges is when I actually want to be
able to send network traffic to multiple arbitrary interfaces connected
to the bridge. I do neither need, nor want bridges when I want to keep
the VMs separated, like when separating a VM in a DMZ from a VM in the
The bridge acts like a hub. Looking at  makes it seem that this is
undesirable --- otherwise there wouldn`t be need for a software switch
to prevent network traffic on a bridge from going to all of the
When there`s a bridge with multiple VMs connected to it, is a software
switch desirable to prevent network traffic on the bridge from going to
interfaces it doesn`t need to go to? If so, isn`t it better not to use
a bridge to begin with?
Can`t we simply have virtual interfaces on the physical host which are
the "other end" of the interfaces showing up in the VMs, without
 seems to suggest to leave all bridges "dangling", i. e. it says
you`re not supposed to connect an interface to the bridge. What`s the
point of a bridge when only a single interface is connected to it?
Knowledge is volatile and fluid. Software is power.
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