[arch-general] tap device

[Paul Gideon Dann]

On Monday 17 Mar 2014 12:00:10 Mauro Santos wrote:
> I suspect we might have been talking about 2 different things all along.
> What I and Arnaud have been talking about is the tap interface on the
> host, not the interface inside the container, which of course should be
> properly configured by the OS inside the container.
> 
> The OS inside the container has no way to bring the tap interface on
> the host up so there would be no network connectivity even though the
> interface on the container side was properly configured and brought up.

That would indeed make sense, but when I asked about this:

On Wednesday 12 Mar 2014 17:32:27 arnaud gaboury wrote:
>> In that case, I'm curious to find out if you find that setting the host0
>> interface up in the container also brings the vb-dahlia interface up on
>> the host?
> 
> On container :
> 
> gab at dahlia ➤➤ ~ % ip addr
> 2: host0: <BROADCAST,ALLMULTI,AUTOMEDIA,UP,LOWER_UP> mtu 1500 qdisc
> pfifo_fast state UP group default qlen 1000
>     link/ether 56:84:f7:39:43:c7 brd ff:ff:ff:ff:ff:ff
>     inet 192.168.1.94/24 brd 192.168.1.255 scope global host0
>        valid_lft forever preferred_lft forever
>     inet6 fe80::5484:f7ff:fe39:43c7/64 scope link
>        valid_lft forever preferred_lft forever
> 
> gab at dahlia ➤➤ ~ # ip link set dev host0 down
> gab at dahlia ➤➤ ~ % ip addr
> 2: host0: <BROADCAST,ALLMULTI,AUTOMEDIA> mtu 1500 qdisc pfifo_fast
> state DOWN group default qlen 1000
>     link/ether 56:84:f7:39:43:c7 brd ff:ff:ff:ff:ff:ff
>     inet 192.168.1.94/24 brd 192.168.1.255 scope global host0
>        valid_lft forever preferred_lft forever
> 
> Now looking on host :
> gabx at hortensia ➤➤ ~ % ip addr
> 4: vb-dahlia: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc
> pfifo_fast master br0 state DOWN group default qlen 1000
>     link/ether 8e:a4:c3:8c:cc:89 brd ff:ff:ff:ff:ff:ff
>     inet 192.168.1.94/24 brd 192.168.1.255 scope global vb-dahlia
>        valid_lft forever preferred_lft forever
>     inet6 fe80::8ca4:c3ff:fe8c:cc89/64 scope link
>        valid_lft forever preferred_lft forever
> 
> 
> It was UP before I brought vb down. So you have your answer : yes.

...buy maybe it doesn't work the other way---bringing the interface up after boot? Anyway, 
this was just a matter of curiosity for me, really. I'm glad you guys got things working the 
way you wanted.

Paul