On Fri, May 22, 2015 at 2:12 PM, Alexander Holler [off-list ref] wrote:

quoted

Bridge doesn't have an underlying link, so no LINK_NETNSID. LINK_NETNSID
is only added when its underlying link is in a different netns.

I'm using "link" similiar as interface. Maybe I've no idea what the
attribute LINK:NETSID really means, but I've understood it as the one
attribute which indicates the namespace an interface (or link), br0 in my
example, lives in.

It is for an underlying link for example: a veth pair is a link for each other,
a tunnel device has a link to transmit packets.

Bridge and bonding are master devices where "slaves" (or ports for bridge)
can join.

netns doesn't have a name or id by nature, we assign it a name by binding
mount some /proc file, these LINK_NETNSID's are not absolutely unique either,
just relatively.