Ticket #5100 (closed defect: fixed)
PCnet FAST-III not working in bridged mode while Intel desktop does
|Reported by:||Neighbour||Owned by:|
|Version:||VirtualBox 3.0.6||Keywords:||bridge pcnet packetloss dhcp|
For some reason, when the VM's nic is bridged with the host's nic, packets destined for the VM are not picked up by the bridge interface. Test scenario: Capture for VM's MAC on dhcpserver, with the command: tcpdump -n -i eth1 -w vm_dhcpserver.cap ether src 08:00:27:24:BC:30 or ether dst 08:00:27:24:BC:30 or ether dst ff:ff:ff:ff:ff:ff Capture on the VM's host using wireshark, on the interface with which the VM is bridged. Capture the VM's nic using vboxmanage modifyvm --nictrace. Boot the VM, execute 'ifdown eth0' and then 'ifup eth0' and wait until the prompt returns. Save a screenshot of the VM window. Stop the captures and shut down the guest.
The above has been done for both situations (PCnet FAST-III and Intel Desktop adapter). As you can see, there are outgoing packets, which are responded to by the DHCPserver, but for some reason they never make it back to the VM. Strangely enough, the DHCPreplies are *not* picked up using wireshark on the host, but *are* picked up in the nictrace when using the Intel Desktop NIC in the guest.