Vista - network problem; ip address conflict

When I start virtual machine (winxp home) I get a message on the host
saying: "there is an IP address conflict with another system on the network".
It later says this on the guest, too. I already tried disabling my firewall
(I have Symantec Endpoint protection), and tried (but failed) to change the
IP address on the guest manually (What I got was "the static IP address you
have assigned is being used by another system on the network" (message is not
exact, will try to get exact message in next response)).

I don't know how this happened, because it worked before and I don't know of
doing any change, such as installing a program or changing network adapters.

Thanks in advance.

"penguin" <penguin@xxxxxx> wrote in message
news:F942CED2-C69A-4267-A167-3BB9E7A2B3C9@xxxxxx
Firstly, you should be able to fix this fairly easily, depending on how your
network is configured. Assuming you have a router (or some other device
acting as a DHCP server), make sure that your virtual machine is configured
to receive an IP address automatically, not manually...


--
Mark Rae
ASP.NET MVP
http://www.markrae.net

Very, very strange.
It suddenly works!?!

That's weird, because all I did was wake my pc from standby (although I did
reboots when I saw this error).

Anyways, what I was going to say was when I used cmd.exe to do this command
"ipconfig /renew" it came up with the following error: "The DHCP client has
obtained an ip address that is alread in use on the network. the local
interface will be disabled until the DHCP client can obtain a new address."
Also, when trying to repair (on guest) it said windows could not repair your
connection because it couldn't renew my ip address.

I'm still confused and don't know why it works now. But hopefully I won't
encounter this again.

Thanks for the prompt response.


"Mark Rae [MVP]" wrote:

"penguin" <penguin@xxxxxx> wrote in message
news:F942CED2-C69A-4267-A167-3BB9E7A2B3C9@xxxxxxI assume you have a router assigning the addresses automatically. I had this
problem repeatedly for awhile suddenly and seemingly out of nowhere. The one
reliable way to fix it was to unplug the router and modem and shut down all
physical computers on the network. Wait a few minutes and then boot the
physical computers as close together as possible. When the desktop appears
plug in the modem, when it synchs then plugin the router. This forces the
router to assign new IP addresses to each computer. I then would start all
my virtual machines and make sure each machine had its own address. I have
two physical computers and several virtual machines on one of the physical
computers. Sometimes, the IP address conflict was between the two physical
computers, but other times it was between a virtual computer and the host
physical computer. There are other ways to fix the problem but none worked
consistently for me and actually usually were a waste of time because they
didn't work and I still had to force the router to reassign new addresses.

I never learned what caused this sudden problem. After a few weeks, it
disappeared as suddenly as it had appeared and I haven't had the problem
since but I read that this problem can appear suddenly, disappear suddenly,
and then reappear months, years later so I might have it again sometime.
This started the first time after I had my older physical computer shutdown
for about 24 hours (usually they are both on 24/7) and when I booted it
after being shutdown I saw, almost immediately on the newer XP computer, the
notice in the systray about an IP address conflict. I think the router
assigned the address the older 98SE computer usually uses to the XP computer
because it was available for 24 hours when the older computer was shut down.

The conflicts between the virtual machines and either one of the physical
machines, or between two virtual machines, were really puzzling and nothing
I tried (after Googling the problem) fixed it reliably except the
irritating, time consuming method I mentioned above. It did seem though
that if I did not use a virtual machine for several days then it would have
this conflict when I started it but I don't think not using a virtual
machine for days or a week or longer should have anything to do with this
because before I had this problem many times I didn't use a virtual machine
for days or a week or so and had no ip address conflicts. So, the reason for
this sudden problem (and its subsequent sudden disappearance after annoying
me for about a month) remain a mystery.

sorry for the last 2 posts. I wish there was a way to edit your post.

I'm still having problems. I can visit a few sites, but they a) take a long
time to load, or b) don't load at all (cannot connect to server). Also,
downloads are slow (at a rate of about 4 KB/Sec).

I'm not a network guy with TCP, IP, DHCP, Subnet mask, and all that stuff,
so I'm completely clueless on what's going on.

--->Penguin & Melelina:

If this happens again, check your router for a DHCP client table. My
router (Linksys) began issuing double IP addresses quite a few times and
my investigation showed that the DHCP client table had double entries in
it for the same machine, but different IP address. But also there were
the same IP addresses for two or more machines.

In my network, I start and shutdown machines at irregular intervals and
I think this table was getting filled up with bad entries. There was a
button the table page of the router that said, in effect, "Clear the
table". When I did that and restarted the router all the operating
computers were then told to 'ipconfig /renew' and they all got new IP
addresses - that didn't conflict.

I would have to clear the table and restart everything about once a month.

My final solution to this was to turn off DCHP and assign static
addresses on my LAN. It's a pain to do so but since I use two of them
as hosts for gaming having the fixed IP addresses helps in boring a hole
through the router firewall.

GP

The only problem is, I'm not connected to a router! (Until Jan. 15, when I
cancel my dsl and wirelessly connect to my netgear router, connected to a
cable modem)

Shared networking seems to work for me. But is my host PC still safe (with
shared networking) if my guest gets infected (not sharing any files)?

"Grand_Poobah" wrote:

"penguin" <penguin@xxxxxx> wrote in message
newsD3E1EE2-AF26-498E-9865-71546E9809F1@xxxxxx
The thing here, as with 99% of VPC questions, is to consider the virtual
machine as identical in every way to a physical machine. The software
installed on it (both OS and applications) doesn't know that it's running on
a virtual machine - it has no need to know that...

Your guest needs to be protected against malware just as much as every other
machine (physical or virtual) on your network:
http://vpc.visualwin.com/ngfaq.aspx#17


--
Mark Rae
ASP.NET MVP
http://www.markrae.net

Okay, because I thought shared networking means connecting your PC to another
PC which has access to the internet. (Since I've never did this, I don't know
if the two computers can communicate, and any contagious virus on any PC
would be able to replicate on the other PC)

"Mark Rae [MVP]" wrote: