Bridge problems on KVM

[gerger09]

I've configured the bridge using this guide https://help.ubuntu.com/community/KVM/Networking but when I connect using eth0 the host loses connection to the network. The guest machine takes all the connection. How do I configure it in a way that they both have a connection but it's still on bridge mode?

[cmont899]

Please post the contents of your /etc/network/interfaces

[gerger09]

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet manual

# The bridge network interface, used by kvm
auto br0
iface br0 inet dhcp
bridge_ports eth0
bridge_stp off
bridge_fd 0
bridge_maxwait 0

[cmont899]

when I connect using eth0 the host loses connection to the network.

Based on your interface file eth0 is not getting an IP, how are you connecting to the host over eth0?

[gerger09]

Through LAN. I tried setting it on dhcp instead of manual but I still get the same result. For now I removed the bridge so I can connect to the internet using LAN.

[gerger09]

I can access the router's web management interface when connected to the LAN but I am unable to access the Internet when in bridge mode. I've been trying to solve this problem for a month now.

[Dedoimedo]

What kind of network connection is eth0? Wired/wireless?
Dedoimedo

[gerger09]

eth0 is wired

[houstonbofh]

Your interfaces file looks good. Did you install the cap net admin and assign the users correctly? https://help.ubuntu.com/community/KV...MIN_Capability

I am thinking this may be your issue.

And did you see the last line at the bottom of https://help.ubuntu.com/community/KV...ge_on_the_host

If your VM host "freezes" for a few seconds after starting or stopping a KVM guest when using bridged networking, it is because a Linux bridge will take the hardware address of the lowest numbered interface out of all of the connected interface. To work around this, add the following to your bridge configuration:

post-up ip link set br0 address f4:6d:04:08:f1:5f

and replace f4:6d:04:08:f1:5f with the hardware address of a physical ethernet adapter which will always be part of the bridge.

If this does not help, post the results of "ifconfig" in a shell.

[Dedoimedo]

What does your route look like - route -n.
Dedoimedo