IP conflict in Windows XP as guest.

[Tjoeben]

For more than a week now I try to find a solution for this problem. I search every where on the internet, and most of all in this forum. I am now at the end of my Latin so I open this topic.
First I give the information about my system.

The Host:
is a laptop Asus K75V, the processor is a Intel i7-3610QM @ 2.3 GHz. The OS is Windows 10 Home 64 bit. The memory is 6GB. The WiFi-card is a Intel Dual Band Wireless-AC 7260.

The VirtualBox:
I use Oracle VM VirtualBox version 5.0.30 r112061.
Before you say do an update, I had the same problems with v. 5.1.18-114002. But because it has worked in the past, therefore I did a down-date.

The Guest:
Is Windows XP Professional (32 bit) v. 2002 with Service Pack 3. I give them 1 GB of base memory, and I give them 1 CPU from the 8 available.
The network is set as Network Bridge Adapter. Connected with the Intel Dual Band Wireless-AC 7260.
The adapter-type is Pcnet-fast III (Am79C973). And the Promiscuous-modus is set in rejected.

My problem:
When I start the guest I have immediately the message that there is a IP conflict.
The guest is set in DHCP and he get an IP address from my modem/router (Fritz!Box 7490). This is not the same IP address than the Host. The Host get the address 192.168.178.107 and the guest get 192.168.178.102. On my network there are devices that are connected via Ethernet cable, and they have a fix IP address. Devices that are connected by WiFi they get the IP address from DHCP (modem).
The DHCP pool range in the modem is from 192.168.178.101 - 202. That's more than enough for all my wireless devices.
In real there is absolutely no IP address conflict. I have checked over and over again.
The IP address of the Fritz!Box modem is 192.168.178.1.

From out the guest I have internet, that work fine. But I can not make connection to my Ethernet/Modbus gateway. This one is on 192.168.178.4.
When I ping from out the guest to the modem, that will work. Even when I ping tot the Host (107) that work fine. When I ping to all other devices on the network then I get time out in the ping sequence, and I get also the message of the IP conflict.
The program that I use for programming my Modicons communicate via the Ethernet/Modbus Gateway and that program must make connection over TCP/IP and must make direct connection with the Gateway. When I want to do this then I get Time-out.

I have try different combinations in the configuration for the network but with no success.
It has worked in the past, but I don't remember when it is going wrong.
Please HELP.

[BillG]

Have you read this recent thread?

viewtopic.php?f=2&t=82539

[Tjoeben]

Have you read this recent thread?

Thanks for sending me this information. I have study this thread and I don't understand this, sorry.
Where I found VRDE ? This is not a windows command.
I have reset de Router/Modem, and I have reset the MAC address of the guest in the VM virtualbox. But there is nothing that helps.

Is it possible to lead me in the right direction?

Thanks.

[socratis]

This is unfortunately not a VirtualBox question, it's a network resource conflict. If you can't find the answer within your router's logs, I don't think we can help you from here. There are two scenarios where VirtualBox could be involved that I can think of:

• You created a clone and you have the same MAC address for two of your VMs.
• You changed the MAC address of your guest so that it matches one of your network devices.

There is one solution, one you would do in real life as well. Go with a pen and paper and write down the addresses of all your wireless devices. Watch the logs of your router. Figure out who is getting which address.

[Tjoeben]

I did not created a clone, and the MAC address is different from all the other MAC addresses.
In excel I have a list of all my network devices, with all the information in IP, mac etc.
So I can quick check.
On my tablet I have an app called "Fing" and that scan the network and I see no conflicts here.
The strange thing is when I ping to the Fritz!Box (192.168.178.1) that will work, it is a normally reaction.
In the guest (windows XP) I have set the IP address on a fix address (192.168.178.98) and I am sure this address is nowhere else used.
And with that it is still the same problem. Internet will work (from out the guest) ping to the Fritz!Box will work also. But ping to all the other devices will not work.
When I do the ping from out the host there is no problem.
If there was a problem with the network (IP conflict) then it shout there from out the host also. Am I right?
Have you another tip ?

[socratis]

• It's really nice that you have a list of IPs and MACs. Really nice!
• I don't have Fing, but I can imagine what it does. I don't think that it's good enough. Double-check the logs of your router.
• I'm not clear about the error message and its origin: does it come from the WinXP guest? Can you post a screenshot? Does it identify what's the duplicate? Is it IPv4 or IPv6? Disable all IPv6 interfaces wherever you can.
• What's the output of an "ipconfing /all" from the guest?
• As I said, if you're getting a valid IP, if you can ping your host/gateway, if you can ping 8.8.8.8, if you can ping google.com, then VirtualBox has done its job.
• Finally, I'd like you to try a wired connection from your host. Bridged over wireless can be finicky sometimes, and this is not due to VirtualBox, it's because the specification doesn't provide room for Bridged over WiFi.

[Tjoeben]

What have I done:
In the guest TCP/IP v6 disabled. No positive result.
In the Host TCP/IP v6 disable. Everything stay the same, no positive result.

Pings in the guest to:
192.168.178.1 -> OK
192.168.178.107 (Host) -> OK
192.168.178.98 (Guest itself) -> TIME OUT
8.8.8.8 -> OK
Google.com -> OK
192.168.178.4 -> TIME OUT

Pings in the Host:
192.168.178.1 -> OK
192.168.178.107 (Host itself) -> OK
8.8.8.8 -> OK
Google.com -> OK
192.168.178.4 -> OK
192.168.178.98 (Guest) -> NOK I get the message: “Destination host unreachable”.

Then in the guest I set this again in DHCP. This time I get another IP address 192.168.178.111.
Even with this one there is no change. Same problems and no positive result.

The problem is not in VM like you said, I believe you, but where can I search to find the problem ?
I have checked the IP addresses and the MAC's again and again, and I find no conflicts.
Even in the log from the modem/router (Fritz!Box) there is no conflict message.
Test with wired connection, it is not possible at the moment, I try to do this tomorrow.

Thanks a lot to help me so far.

[socratis]

The problem is not in VM like you said, I believe you, but where can I search to find the problem ?

I wouldn't know where to search for this, but most probably in (Windows) networking specific sites.

I'd start taking devices off-line, one-by-one, until I don't get that error anymore.

Good luck.

[Tjoeben]

This time I have try it with wired connection, and this will work. Now I have no error IP conflict.
There is nothing changed in the network, all devices stay connected like before.

Very strange situation.

I now for sure that it has worked with the WiFi card. I don't now what is changed except that there was a update of VM Virtualbox.
Bud I did a step back and I installed the previous version, and that was even no solution.

Ether way I must find a solution that I can do this with WiFi.
Is this maybe a combination of VM Virtualbox with the Intel(R) Dual Band Wireless-AC 7260 ?

[Tjoeben]

Again I do some experiments with VM virtualbox and the network over WiFi.

I discover something strange. After when I start up the guest (Windows XP) I start an IP scanner in the guest. Then I see there are a number of devices on-line.
When I ping to these that will work. When I scan again after a short time then there are a few devices disappear in the scanning list. When I ping these, I get time out.

When I do a scan from out the host, then the scanner find all the devices.

[socratis]

As I said earlier, Bridged and WiFi don't always play nice.

Bridged and wireless don't always play nice. Bridged networking is outside the WLAN specification. Bridging to wireless is not really bridging. The guest shares the MAC of the host and the host does a sort of MAC-NAT translation based on IP addresses. Promiscuous mode doesn't exist in the official WLAN specifications. It may or may not work. Some combinations of Routers/Access Points, WLAN cards and drivers work, some don't. See: Bridging & Wifi - Supported hardware and add your experience. For example, it works fine in my home, but not in my office. Same laptop, same VM. Try to see if it works either with wired bridged or with NAT.

Many wifi routers now try to use unicast link-level destination for broadcast/multicast IP destination. The reasons are explained in http://tools.ietf.org/html/draft-vyncke ... ficient-01 - that is in context of IPv6, but the same logic applies to IPv4 (IPv6 is hit harder since it relies more on multicast). Behavior varies between wifi routers, so you may get bridged setup working with some and not working with others.

If the wifi router that is not working for you just uses unicast delivery for multicast, then 4.3.16 should help (a typical packet capture can be seen in #12207). In this case the host was receiving DHCP replies intended for the guest (broadcast IP, but unicast to host MAC), but was not rewriting MAC address correctly, so the guest was not receiving the packet. If you plug another computer into the wired port of the router to capture DHCP exchange as seen on the wired side, you would see the same DHCP replies sent to ethernet broadcast on the wired connection. So this is just an optimization for wifi that some routers do.

Unfortunately - and this is orthogonal to multicast/unicast issue above - some routers will send DHCP replies to broadcast IP, but to the unicast client MAC address (i.e. guest MAC in this case) fetched from the DHCP request. These packets will never be even seen by the host. I'm afraid the packet captures in comment:14 is an example of that. In the ethernet capture you can see DHCP replies unicast to guest and in the wireless capture you don't see any replies at all. I have one router like this (though it at least uses ethernet broadcast for its DHCP NAKs, so you can see something in the wireless capture .

This latter kind of routers has problems with DHCP, but usually you can work around it by not using DHCP and using static IP instead. E.g. I cannot connect to that router of mine with DHCP, but if I use static IP in the guest then I get normal connectivity. Yes, this is suboptimal , but better than no connectivity if you must use bridged for some reason.