Hi Gerry,

I did seriously consider adding a category for networking in the forum as there have been quite a lot of feedback with respect to KVM networking. I thought that it might be ok to fall under a more general category but your request for this tips the scale for me.

VDE switching was also on my list of topics to start writing about but I would also welcome community participation.

Haydn

I would like to use the VMM gui to manage the guests. But I also need the gui to support changing the networking options. Or does this have to be done by undefining guest and changing .xml then redefining guest??? Still a little confusing as to how you do all these types of things.

Regards,
Gerry

Struggling to get KVM and VDE working together. I spent about eight hours on this with no success. I am able to get the libvirt bridge (virbr0) to work but I cannot figure out how to get the VDE2 tap0 interface working. Here are things that I have tried:

echo "1" > /proc/sys/net/ipv4/ip_forward
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
service iptables save

# my LAN is 192.168.1.0

tunctl
ifconfig tap0 192.168.1.254 netmask 255.255.255.0
vde_switch -tap tap0 (in another terminal)
vdekvm -hda TEST1.img -m 512

ifcfg-eth0 (guest):
BOOTPROTO=static
IPADDR=192.168.1.89
NETMASK=255.255.255.0
GATEWAY=192.168.1.254

In guest, I cannot ping anything on LAN, not even the gateway.

Here is ifconfig (host):
eth0 Link encap:Ethernet HWaddr 00:1A:4D:5E:F6:36
inet addr:192.168.1.15 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::21a:4dff:fe5e:f636/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:74482 errors:0 dropped:0 overruns:0 frame:0
TX packets:23208 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:55338133 (52.7 MiB) TX bytes:2089252 (1.9 MiB)
Interrupt:19 Base address:0x4000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:61305 errors:0 dropped:0 overruns:0 frame:0
TX packets:61305 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:99360931 (94.7 MiB) TX bytes:99360931 (94.7 MiB)

tap0 Link encap:Ethernet HWaddr 00:FF:19:44:D3:13
inet addr:192.168.1.254 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::2ff:19ff:fe44:d313/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:23 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:106 (106.0 b) TX bytes:0 (0.0 b)

virbr0 Link encap:Ethernet HWaddr 00:00:00:00:00:00
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
inet6 addr: fe80::c4ee:d7ff:fe1d:6b15/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4534 errors:0 dropped:0 overruns:0 frame:0
TX packets:7831 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:258603 (252.5 KiB) TX bytes:11633607 (11.0 MiB)

If possible does someone have a working config for KVM w/VDE that I could examine?

Regards,
Gerry

I am seeing this in the terminal where I'm running vde_switch:

# vde_switch -tap tap0
vde_switch: MAC 00:ff:c7:0c:f3:a1 moved from port 1 to port 2
vde_switch: MAC 00:ff:c7:0c:f3:a1 moved from port 1 to port 2
vde_switch: MAC 00:ff:c7:0c:f3:a1 moved from port 1 to port 2
vde_switch: MAC 00:ff:c7:0c:f3:a1 moved from port 1 to port 2
vde_switch: MAC 00:ff:c7:0c:f3:a1 moved from port 1 to port 2
vde_switch: MAC 00:ff:c7:0c:f3:a1 moved from port 1 to port 2

This is the MAC address for tap0 that it is moving. What does this mean?

Regards,
Gerry

> Here is ifconfig (host):
> eth0 Link encap:Ethernet HWaddr 00:1A:4D:5E:F6:36
> inet addr:192.168.1.15 Bcast:192.168.1.255 Mask:255.255.255.0
....
> tap0 Link encap:Ethernet HWaddr 00:FF:19:44:D3:13
> inet addr:192.168.1.254 Bcast:192.168.1.255 Mask:255.255.255.0

It seems that eth0 and tap0 are on the same network on the host.
Please try to change the subnet used on the VDE (tap0 and eth0 on guest).

renzo

I've been successfully using VDE as the network connection for VMs for a long time now and as part of some additions to the management side I thought I should document how VDE is configured and used before I forget the nuances.

I've written it up in my Wiki, in the article "Virtual Machines With VDE Networking"

I hope it helps - I remember how much brain-ache it caused me initially because all I could find was documentation fragments, clues, and lots of misleading generalisations.

I've registered an account here after posting the previous comment about my Wiki tutorial, so if you have questions you know where to find me.