I have the following settings at home up and running for over 2 years and everything is fine.
They are a Debian VBox Host, and two virtual machine (vm1, vm2) using birdged adapter network.
vm1 (192.168.1.1) serves as a lamp server with virtualhost. (debian)
vm2 (192.168.1.2) serves as a normal desktop. (archlinux)
I setup dnsmasq on my router (tomatousb) so that I can use hostname as url input on browser on vm2.

Recently, I run wireshark/tcpdump on the VBox Host and expect to see some packets between vm1 and vm2 when I'm browsing website on vm1 from vm2. But out of my surprise, no such packets are found!

I even freshly build another debain lamp server without iptables to double check. Seems that "not finding such packet" is normal!!
So, some of my basic understanding is wrong? Or what else is happening? Would somebody be kind enough to point it out.

Thanks a lot


P.S. Sorry if I post in a wrong forum. Please move it to wherever appropriate.

Are you telling tcpdump the correct interface to look at? What is the exact tcpdump command?

Thank you for your reply.

I have only one network card on the VBox Host. I use the most basic option.

If I start a ssh session from vm2 to vm1, I can see packets with ip.src and ip.dst pair of vm1<->vm2. Readlly wonder why it is not for web browsing.


-------------------------------- edit
Just wonder if I did something on wireshark before that makes it filter out http packet.

So I just run a test
No ip.vm1 ip.vm2 pair on one line found.

You may have only one network card, but very few systems have only one interface. You can list the interfaces with the command On my box, tcpdump listens on lo if I don't specify with -i.

ip link lists 3 interface: lo eth0 vboxnet0

When I apply them to tcpdump, vboxnet0 replies that the device is not up, lo replies zero packets captured, eth0 behaves as the original problem.

Is this question too basic or too strange?