[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] Qemu-KVM VETH
From: |
Tim Epkes |
Subject: |
Re: [Qemu-devel] Qemu-KVM VETH |
Date: |
Fri, 20 Sep 2013 11:48:50 -0400 |
Stefan,
The problem aI face is that a bridge in the middle ( using taps) breaks LLDP ( L2 discovery protocol) and should break ISIS as well. Sockets aren't bad, but if for some reason I take the listener VM down and bring back up, then I have to bring down all connector VMs, which chains on itself if there is a lot of connectivity defined. When UDP was available that wasn't an issue.
Anyway, that is how I came to VETHs. I am aware that you can use UDP multicast, but performance past one hop is extremely poor ( resulting in 3 of 5 pings to be lost. Thanks
Tim
On Friday, September 20, 2013, Stefan Hajnoczi wrote:
On Thu, Sep 19, 2013 at 05:31:01PM -0400, Tim Epkes wrote:
> Any plans to provide VETH support for Qemu-KVM. It is a great pt-pt tie
> when when connecting to KVM's on the same machine. I have multiple reasons
> for doing so (one is educational). Thanks
QEMU already supports -netdev tap (if you want to use the host Linux
networking stack) and -netdev socket (if you just want point-to-point
tunneling).
The veth driver isn't suitable for QEMU's use case. QEMU is a userspace
process that wants to inject/extract Ethernet frames. That's exactly
what the tun (tap) driver does. veth is useful for containers where you
want a Linux network interface that is handled by the host network stack.
Two solutions for point-to-point:
1. Run two guests with -netdev tap. Put the interfaces on a software
bridge (see brctl(8)). Or you could also use IP forwarding instead
of a bridge if you like.
2. Run two guests with -netdev socket. They send Ethernet frames
directly to each other.
See the qemu man page for configuration details.
Stefan
- [Qemu-devel] Qemu-KVM VETH, Tim Epkes, 2013/09/19
- Re: [Qemu-devel] Qemu-KVM VETH, Stefan Hajnoczi, 2013/09/20
- Re: [Qemu-devel] Qemu-KVM VETH,
Tim Epkes <=
- Re: [Qemu-devel] Qemu-KVM VETH, Stefan Hajnoczi, 2013/09/20
- Re: [Qemu-devel] Qemu-KVM VETH, Tim Epkes, 2013/09/20
- Re: [Qemu-devel] Qemu-KVM VETH, Tim Epkes, 2013/09/24
- Re: [Qemu-devel] Qemu-KVM VETH, Stefan Hajnoczi, 2013/09/25
- Re: [Qemu-devel] Qemu-KVM VETH, Tim Epkes, 2013/09/25