Comments on Alan Tan: QEMU TAP bridge network configuration

I had to run qemu as root to get this to work - ot...

2009-12-17T07:50:35.077-05:00

I had to run qemu as root to get this to work - otherwise it complains about an ioctl on /dev/net/tun failing. I tried chmod and tunctl but couldn't get it to work as non-root.

Thanks for the simple instructions. As another p...

2009-12-17T05:53:32.056-05:00

Thanks for the simple instructions.

As another poster pointed out, "nameif -r" doesn't work, you can use "nameif reth0 00:aa:bb:cc:dd:ee" instead (replace with your MAC address), or specify this in /etc/mactab (see man nameif for more).

One thing that wasn't obvious for me is the actual qemu syntax: "qemu -net tap" won't work, instead you need to do "qemu -net nic -net tap".

Great article, thanks! FYI, I put these three lin...

2009-09-21T02:47:52.178-04:00

Great article, thanks!

FYI, I put these three lines in my /etc/qemu-ifup:

sudo /usr/sbin/tunctl -t tap0
sudo /sbin/ifconfig $1 0.0.0.0 promisc up
sudo /usr/sbin/brctl addif br0 $1

should we give the same mac address to nic in gues...

2008-10-31T06:28:00.000-04:00

should we give the same mac address to nic in guest os as held by tap device?

I am still unable to get it to work. What ip/netwo...

2008-10-31T06:26:00.000-04:00

I am still unable to get it to work. What ip/network address should I provide to tap device? What ip/network should be given to nic in guest os?

A minor nitpic: nameif -r doesn't workYou might wa...

2008-09-03T07:54:00.000-04:00

A minor nitpic: nameif -r doesn't work
You might want to use "ip link set eth0 name reth0" instead

Great explanations Alan!! Unfortunately, it seems ...

2008-06-13T16:11:00.000-04:00

Great explanations Alan!!

Unfortunately, it seems that there is a lack of (good) documentation about bridged networking in QEMU/KVM. I followed instructions from a couple of sources on the web, telling me to do A, then B, C, etc, without offering an adequate reasoning. I ended up totally confused, and it took me a whole day to figure out why I was supposed to connect things in the way I was being told. Finally I found this article of yours. Well done!

Thank you very much, indeed.

V.I

You should be able to specify "-net nic .... -net ...

2008-05-14T14:36:44.678-04:00

You should be able to specify "-net nic .... -net tap" like below:

qemu -boot c -hda /hd1 -m 1024 -localtime -net nic,macaddr1=0e:50:40:17:39:01
-net tap

Hi,how would one go about configuring a specific m...

2008-04-10T08:00:00.000-04:00

Hi,

how would one go about configuring a specific mac address to present to the guest on this tap/bridge configuration?

It appears that macaddr= can only be set in -net nic mode ....

Your a Genius!One note: as mentioned in the commen...

2008-03-03T04:43:00.000-05:00

Your a Genius!
One note: as mentioned in the comment above you have to create a tap device. To do this (on debian at least) you need uml-utilities and use tunctl -t tap0.
Cheers

Thanks a lot for your document !!!Finally I unders...

2007-10-28T22:17:00.000-04:00

Thanks a lot for your document !!!

Finally I understood the reason of being of bridge. I've read a lot of documents, saying to use iptables and others complex things, In layer 2 iptables?....

Only one comment to your doc, tap device must be created before to sucessfully attach it to the bridge.

In my distro, rename interface is:

nameif reth0 00:13:D4:3F:92:E0

where 00:.... is the MAC address of physical interface.

THANKS A LOT FOR YOUR HELP

Alan,Thanks for your suggestion on bridging TAP in...

2007-08-23T12:21:00.000-04:00

Alan,

Thanks for your suggestion on bridging TAP interfaces; I was one of those guys trying to tweak multiple TAPs and routing between them.... bridging is far easier!

And you are right about the lack of quality documentation.

Mark.
lau.nam.mee[at]gmail.com