11:18 a.m.
Greetings,
I have two vms (vm1 and vm2) connected via a bridge named br1.
libvirt creates two taps, tap0 and tap1
I'm trying to rename them to some thing more meaningful for starts.
I assume that I cannot use vnet-vm1 or vnet-vm2 so I decided to configure it like this:
vm1:
<interface type='bridge'>
<source bridge='br1'/>
<target dev='vnet1'/>
</interface>
vm2:
<interface type='bridge'>
<source bridge='br1'/>
<target dev='vnet2'/>
</interface>
but when start the vms, the iface names are still tap1 and tap2. am I doing something
wrong?
in addition, I want to add the host to br1, so I ran this after the bridge exists: ip link
set dev tap3 master br1
I see it when I run brctl show br1, but I'm unable to get ip, am I doing something
wrong here too?
Thanks,
Dagg.
11:43 a.m.
New subject: reconfiguring a two vms bridge to two vms + the host with
proper iface naming
On Thu, Oct 24, 2024 at 06:18:26PM +0200, daggs via Users wrote:
Greetings,
I have two vms (vm1 and vm2) connected via a bridge named br1.
libvirt creates two taps, tap0 and tap1
I'm trying to rename them to some thing more meaningful for starts.
I assume that I cannot use vnet-vm1 or vnet-vm2 so I decided to configure it like this:
vm1:
<interface type='bridge'>
<source bridge='br1'/>
<target dev='vnet1'/>
</interface>
vm2:
<interface type='bridge'>
<source bridge='br1'/>
<target dev='vnet2'/>
</interface>
but when start the vms, the iface names are still tap1 and tap2. am I doing something
wrong?
I didn't think libvirt created devices with 'tapXXX' naming, all our
generated names should be 'vnetXXX', and we reserve 'vnet' as a prefix
for our own use and will thus discard any such name if the user specifies
it in the XML.
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
11:47 a.m.
New subject: reconfiguring a two vms bridge to two vms + the host with
proper iface naming
Sent: Thursday, October 24, 2024 at 7:43 PM
From: "Daniel P. Berrangé" <berrange(a)redhat.com>
To: "daggs" <daggs(a)gmx.com>
Cc: users(a)lists.libvirt.org
Subject: Re: reconfiguring a two vms bridge to two vms + the host with proper iface
naming
On Thu, Oct 24, 2024 at 06:18:26PM +0200, daggs via Users wrote:
> Greetings,
>
> I have two vms (vm1 and vm2) connected via a bridge named br1.
> libvirt creates two taps, tap0 and tap1
>
> I'm trying to rename them to some thing more meaningful for starts.
> I assume that I cannot use vnet-vm1 or vnet-vm2 so I decided to configure it like
this:
> vm1:
> <interface type='bridge'>
> <source bridge='br1'/>
> <target dev='vnet1'/>
> </interface>
>
> vm2:
> <interface type='bridge'>
> <source bridge='br1'/>
> <target dev='vnet2'/>
> </interface>
>
> but when start the vms, the iface names are still tap1 and tap2. am I doing
something wrong?
I didn't think libvirt created devices with 'tapXXX' naming, all our
generated names should be 'vnetXXX', and we reserve 'vnet' as a prefix
for our own use and will thus discard any such name if the user specifies
it in the XML.
With regards,
Daniel
this is my output:
utils-server:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host proto kernel_lo
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen
1000
link/ether 52:54:00:ab:30:dc brd ff:ff:ff:ff:ff:ff
8: br1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group
default qlen 1000
link/ether 52:54:00:6b:1b:92 brd ff:ff:ff:ff:ff:ff
10: tap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br1
state UNKNOWN group default qlen 1000
link/ether fe:7f:ea:04:9d:97 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc7f:eaff:fe04:9d97/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
11: tap1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br1
state UNKNOWN group default qlen 1000
link/ether fe:47:d8:75:ce:ee brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc47:d8ff:fe75:ceee/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
> --
> |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org -o- https://fstop138.berrange.com :|
> |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
>
>
9:35 a.m.
New subject: reconfiguring a two vms bridge to two vms + the host with proper
iface naming
On 10/24/24 12:47 PM, daggs via Users wrote:
> Sent: Thursday, October 24, 2024 at 7:43 PM
> From: "Daniel P. Berrangé" <berrange(a)redhat.com>
> To: "daggs" <daggs(a)gmx.com>
> Cc: users(a)lists.libvirt.org
> Subject: Re: reconfiguring a two vms bridge to two vms + the host with proper iface
naming
>
> On Thu, Oct 24, 2024 at 06:18:26PM +0200, daggs via Users wrote:
>> Greetings,
>>
>> I have two vms (vm1 and vm2) connected via a bridge named br1.
>> libvirt creates two taps, tap0 and tap1
>>
>> I'm trying to rename them to some thing more meaningful for starts.
>> I assume that I cannot use vnet-vm1 or vnet-vm2 so I decided to configure it like
this:
>> vm1:
>> <interface type='bridge'>
>> <source bridge='br1'/>
>> <target dev='vnet1'/>
>> </interface>
>>
>> vm2:
>> <interface type='bridge'>
>> <source bridge='br1'/>
>> <target dev='vnet2'/>
>> </interface>
>>
>> but when start the vms, the iface names are still tap1 and tap2. am I doing
something wrong?
>
> I didn't think libvirt created devices with 'tapXXX' naming,
The one place this isn't true is for guests started with unprivileged
libvirt; it uses the qemu-bridge-helper to create the tap device and
connect it to the bridge, and uses names of the form "tapX". So I'm
fairly certain that daggs is running the guests as a normal user, not as
root.
> all our
> generated names should be 'vnetXXX', and we reserve 'vnet' as a
prefix
> for our own use and will thus discard any such name if the user specifies
> it in the XML.
Beyond that, when running guests in non-privileged mode, libvirt has no
control over the tap device name under any vircumstances, and so the
target dev name would be ignored no matter what it was. In the end this
all means that you can't control what name the tap devices have (and it
shouldn't matter other than cosmetic)
As for connecting the bridge device to the *host's* IP stack (which I
*think* you alluded to in the subject line), that must be done outside
of libvirt in the host's network config, essentially just move the IP
configuration from the physical ethernet you want attached to the
bridge, over to the bridge itself (removing it from the physical device).
>
>
> With regards,
> Daniel
this is my output:
utils-server:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host proto kernel_lo
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen
1000
link/ether 52:54:00:ab:30:dc brd ff:ff:ff:ff:ff:ff
8: br1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group
default qlen 1000
link/ether 52:54:00:6b:1b:92 brd ff:ff:ff:ff:ff:ff
10: tap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br1
state UNKNOWN group default qlen 1000
link/ether fe:7f:ea:04:9d:97 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc7f:eaff:fe04:9d97/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
11: tap1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br1
state UNKNOWN group default qlen 1000
link/ether fe:47:d8:75:ce:ee brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc47:d8ff:fe75:ceee/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
> --
> |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org -o- https://fstop138.berrange.com :|
> |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
>
>
12:43 p.m.
New subject: reconfiguring a two vms bridge to two vms + the host with
proper iface naming
Sent: Monday, October 28, 2024 at 4:35 PM
From: "Laine Stump" <laine(a)redhat.com>
To: "daggs" <daggs(a)gmx.com>, berrange(a)redhat.com
Cc: users(a)lists.libvirt.org
Subject: Re: reconfiguring a two vms bridge to two vms + the host with proper iface
naming
On 10/24/24 12:47 PM, daggs via Users wrote:
>
>
>> Sent: Thursday, October 24, 2024 at 7:43 PM
>> From: "Daniel P. Berrangé" <berrange(a)redhat.com>
>> To: "daggs" <daggs(a)gmx.com>
>> Cc: users(a)lists.libvirt.org
>> Subject: Re: reconfiguring a two vms bridge to two vms + the host with proper
iface naming
>>
>> On Thu, Oct 24, 2024 at 06:18:26PM +0200, daggs via Users wrote:
>>> Greetings,
>>>
>>> I have two vms (vm1 and vm2) connected via a bridge named br1.
>>> libvirt creates two taps, tap0 and tap1
>>>
>>> I'm trying to rename them to some thing more meaningful for starts.
>>> I assume that I cannot use vnet-vm1 or vnet-vm2 so I decided to configure it
like this:
>>> vm1:
>>> <interface type='bridge'>
>>> <source bridge='br1'/>
>>> <target dev='vnet1'/>
>>> </interface>
>>>
>>> vm2:
>>> <interface type='bridge'>
>>> <source bridge='br1'/>
>>> <target dev='vnet2'/>
>>> </interface>
>>>
>>> but when start the vms, the iface names are still tap1 and tap2. am I doing
something wrong?
>>
>> I didn't think libvirt created devices with 'tapXXX' naming,
The one place this isn't true is for guests started with unprivileged
libvirt; it uses the qemu-bridge-helper to create the tap device and
connect it to the bridge, and uses names of the form "tapX". So I'm
fairly certain that daggs is running the guests as a normal user, not as
root.
you are correct, my bad
>> all our
>> generated names should be 'vnetXXX', and we reserve 'vnet' as a
prefix
>> for our own use and will thus discard any such name if the user specifies
>> it in the XML.
Beyond that, when running guests in non-privileged mode, libvirt has no
control over the tap device name under any vircumstances, and so the
target dev name would be ignored no matter what it was. In the end this
all means that you can't control what name the tap devices have (and it
shouldn't matter other than cosmetic)
As for connecting the bridge device to the *host's* IP stack (which I
*think* you alluded to in the subject line),
correct again....
that must be done outside
of libvirt in the host's network config, essentially just move the IP
configuration from the physical ethernet you want attached to the
bridge, over to the bridge itself (removing it from the physical device).
not sure
I follow, the bridge has no physical ethernet, it has 3 taps.
tap0 for vm1, tap1 for vm2 and vnet0 for the host which I create and attach to the bridge
using the commands stated in the original mail.
but vnet0 is reporting No Carrier
>
> >>
> >>
> >> With regards,
> >> Daniel
> > this is my output:
> > utils-server:~# ip a
> > 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
default qlen 1000
> > link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> > inet 127.0.0.1/8 scope host lo
> > valid_lft forever preferred_lft forever
> > inet6 ::1/128 scope host proto kernel_lo
> > valid_lft forever preferred_lft forever
> > 2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group
default qlen 1000
> > link/ether 52:54:00:ab:30:dc brd ff:ff:ff:ff:ff:ff
> > 8: br1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
group default qlen 1000
> > link/ether 52:54:00:6b:1b:92 brd ff:ff:ff:ff:ff:ff
> > 10: tap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
master br1 state UNKNOWN group default qlen 1000
> > link/ether fe:7f:ea:04:9d:97 brd ff:ff:ff:ff:ff:ff
> > inet6 fe80::fc7f:eaff:fe04:9d97/64 scope link proto kernel_ll
> > valid_lft forever preferred_lft forever
> > 11: tap1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
master br1 state UNKNOWN group default qlen 1000
> > link/ether fe:47:d8:75:ce:ee brd ff:ff:ff:ff:ff:ff
> > inet6 fe80::fc47:d8ff:fe75:ceee/64 scope link proto kernel_ll
> > valid_lft forever preferred_lft forever
> >
> >
> >
> >> --
> >> |: https://berrange.com -o- https://www.flickr.com/photos/dberrange
:|
> >> |: https://libvirt.org -o- https://fstop138.berrange.com
:|
> >> |: https://entangle-photo.org -o- https://www.instagram.com/dberrange
:|
> >>
> >>
> >
>
>
24
days inactive
29
days old
4 comments
3 participants
participants (3)
-
daggs -
Daniel P. Berrangé -
Laine Stump