networking problems between vms

networking problems between vms

[Volker Cordes]

Hello,

I'm running 4 virtual machines on one host, connected by a network
bridge on the host (IP 192.168.0.1). All TAP devices get added to that
bridge when starting the vm:

brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.52fd3fbd954e       no              tap01
                                                        tap02
                                                        tap03
                                                        tap04

I use virtio networking (but tried the e1000 driver, too). The vms have
static IPs 192.168.0.250 - 253 with 192.168.0.1 as the gateway.
Connecting from the host to the machines and from the machines to the
internet works just fine. The problem lies in connecting from one
machine to another. There is a 30 seconds delay until the connection
gets established, I tried ssh, http and mysql. After the connection is
there, the speed seems to be normal.

Any hints would be appreciated.

Thanks,
Volker

Re: networking problems between vms

[Avi Kivity]

On 02/07/2011 11:51 AM, Volker Cordes wrote:
> Hello,
>
> I'm running 4 virtual machines on one host, connected by a network
> bridge on the host (IP 192.168.0.1). All TAP devices get added to that
> bridge when starting the vm:
>
> brctl show
> bridge name     bridge id               STP enabled     interfaces
> br0             8000.52fd3fbd954e       no              tap01
>                                                          tap02
>                                                          tap03
>                                                          tap04
>
> I use virtio networking (but tried the e1000 driver, too). The vms have
> static IPs 192.168.0.250 - 253 with 192.168.0.1 as the gateway.
> Connecting from the host to the machines and from the machines to the
> internet works just fine. The problem lies in connecting from one
> machine to another. There is a 30 seconds delay until the connection
> gets established, I tried ssh, http and mysql. After the connection is
> there, the speed seems to be normal.
>
> Any hints would be appreciated.
>

Does

   brctl setfd br0 0.5

help?

-- 
error compiling committee.c: too many arguments to function

Re: networking problems between vms

[Volker Cordes]

Avi Kivity <avi <at> redhat.com> writes:

> 
> On 02/07/2011 11:51 AM, Volker Cordes wrote:
> > Hello,
> >
> > I'm running 4 virtual machines on one host, connected by a network
> > bridge on the host (IP 192.168.0.1). All TAP devices get added to that
> > bridge when starting the vm:
> >
> > brctl show
> > bridge name     bridge id               STP enabled     interfaces
> > br0             8000.52fd3fbd954e       no              tap01
> >                                                          tap02
> >                                                          tap03
> >                                                          tap04
> >
> > I use virtio networking (but tried the e1000 driver, too). The vms have
> > static IPs 192.168.0.250 - 253 with 192.168.0.1 as the gateway.
> > Connecting from the host to the machines and from the machines to the
> > internet works just fine. The problem lies in connecting from one
> > machine to another. There is a 30 seconds delay until the connection
> > gets established, I tried ssh, http and mysql. After the connection is
> > there, the speed seems to be normal.
> >
> > Any hints would be appreciated.
> >
> 
> Does
> 
>    brctl setfd br0 0.5
> 
> help?
> 

No does not help. The bridge is created in /etc/network/interfaces (debian):

iface tap0 inet manual
auto br0
iface br0 inet static
  bridge_ports          tap0
  bridge_stp            off
  bridge_maxwait        0
  bridge_fd             0
  address 192.168.0.1
  netmask 255.255.255.0

I'm using kvm version:
QEMU emulator version 0.13.0 (qemu-kvm-0.13.0 Debian 0.13.0+dfsg-2), Copyright 
(c) 2003-2008 Fabrice Bellard
with kvm_intel

on kernel:
Linux example.com 2.6.32-5-amd64 #1 SMP Wed Jan 12 03:40:32 UTC 2011 x86_64
GNU/Linux

I also tried -no-kvm, -no-kvm-irqchip and -no-kvm-pit. Didn't help.

Even connecting to the local machine has this 30 seconds delay (only if I use
192..., localhost is ok)

Re: networking problems between vms

[Avi Kivity]

On 02/07/2011 01:27 PM, Volker Cordes wrote:
> Avi Kivity<avi<at>  redhat.com>  writes:
>
> >
> >  On 02/07/2011 11:51 AM, Volker Cordes wrote:
> >  >  Hello,
> >  >
> >  >  I'm running 4 virtual machines on one host, connected by a network
> >  >  bridge on the host (IP 192.168.0.1). All TAP devices get added to that
> >  >  bridge when starting the vm:
> >  >
> >  >  brctl show
> >  >  bridge name     bridge id               STP enabled     interfaces
> >  >  br0             8000.52fd3fbd954e       no              tap01
> >  >                                                           tap02
> >  >                                                           tap03
> >  >                                                           tap04
> >  >
> >  >  I use virtio networking (but tried the e1000 driver, too). The vms have
> >  >  static IPs 192.168.0.250 - 253 with 192.168.0.1 as the gateway.
> >  >  Connecting from the host to the machines and from the machines to the
> >  >  internet works just fine. The problem lies in connecting from one
> >  >  machine to another. There is a 30 seconds delay until the connection
> >  >  gets established, I tried ssh, http and mysql. After the connection is
> >  >  there, the speed seems to be normal.
> >  >
> >  >  Any hints would be appreciated.
> >  >
> >
> >  Does
> >
> >     brctl setfd br0 0.5
> >
> >  help?
> >
>
> No does not help. The bridge is created in /etc/network/interfaces (debian):
>
> iface tap0 inet manual
> auto br0
> iface br0 inet static
>    bridge_ports          tap0
>    bridge_stp            off
>    bridge_maxwait        0
>    bridge_fd             0
>    address 192.168.0.1
>    netmask 255.255.255.0
>
> I'm using kvm version:
> QEMU emulator version 0.13.0 (qemu-kvm-0.13.0 Debian 0.13.0+dfsg-2), Copyright
> (c) 2003-2008 Fabrice Bellard
> with kvm_intel
>
> on kernel:
> Linux example.com 2.6.32-5-amd64 #1 SMP Wed Jan 12 03:40:32 UTC 2011 x86_64
> GNU/Linux
>
> I also tried -no-kvm, -no-kvm-irqchip and -no-kvm-pit. Didn't help.
>
> Even connecting to the local machine has this 30 seconds delay (only if I use
> 192..., localhost is ok)
>
>

Check reverse dns resolution and firewall rules.  Don't seem to be a kvm 
problem.

-- 
error compiling committee.c: too many arguments to function

Re: networking problems between vms

[Volker Cordes]

Avi Kivity <avi <at> redhat.com> writes:


> Check reverse dns resolution and firewall rules.  Don't seem to be a kvm 
> problem.
> 

Thanks for the hint, it really was a typo in the zone config. Wouldn't have
thought to look there.

Volker