Duplicate IPs in windoes7 guests

[bobptz]

Hello

I am running 3 pcs with Ubuntu, each one having a windows7 guest. 2 guests complain that they detected duplicate IPs in the network.

I examined the MAC address generated by VB. Some where identical (with other guests), so I changed them to make them unique. However the duplicate IPs problem remained.

The network settings I use for all guests are:
BRIDGED ADAPTER
PARAVIRTUALIZED NETWORK
PROMISCUOUS MODE: DENY

How can I fix this please?

I tried to check the list of connected IPs in the router (OpenWRT). However it did not list all connected devices, ie 3 hosts + 3 guests. Maybe it was not updating often enough.

[socratis]

How can I fix this please?

1. Double-check that *no* duplicate MACs exist. Write them all down. Even better if you do it on a spreadsheet.
2. Shut everything down, including physical hosts. For the VMs shut them down, don't simply save-state them
3. Wait 10', restart your whole LAN.

[bobptz]

@Socratis

I'll do what you said.

Quick question:
The MAC address displayed on the VB settings, I should see the same number when I run IPCONFIG in Windows command line, correct?

[socratis]

Correct.
But don't go through the Win guests "ipconfig", it's going to slow your noting down the MACs by a factor of 100!

I have a small script that gets all the MACs for all the guests, but it's OSX/Linux only. I'll see if I can make it a Windows batch file as well...

[bobptz]

Hi

I just noticed that on one laptop VB uses two Adapters. The enp0s25 (cable) with a MAC ending in 0E and the wlp8s0 (wifi) ending in DA. However in windows, when I run ipconfig /all, it reports the mac addresses inverted:
DA for the cable connected connection and 0E for the wifi connection.

Could this be a problem?

Is this something I should change or care for?

[socratis]

Ending in? Why wouldn't you post the complete MACs so that we know what we're talking about? I don't want to start guessing what the other digits are, seriously now...

And in the guest, the MACs are virtual, fake, not a lot to do with your host actually...

[bobptz]

This is what I noticed in one of the laptops. In the VB VM settings->Network there are two Adapters:
1) enp0s25 (cable) with a MAC = 080027BF7D0E
2) wlp8s0 (wifi) with a MAC = 080027421EDA

However in windows7 Guest, when I run ipconfig /all, it reports the mac addresses inverted:

Ethernet adapter wired:
Physical address: 080027421EDA
Autoconfiguration IPv4 Address : 169.254.98.140 (Preferred)

Ethernet adapter wifi:
Physical address: 080027BF7D0E
IPv4 Address : 192.168.1.135 (Preferred)

[socratis]

1. I'll assume that you're talking about the "Bridged to" part, because that's the only place you're going to see "enp0s25" and "wlp8s0".
2. There's no WiFi in a guest, so you can't be possibly seeing a WiFi.
3. MACs inverted... Inverted from what exactly? In your VM you should have 2 NICs. How do you tell which is which, I don't see it...

[mpack]

Is it possible that this OP has bridged to a host USB WiFi dongle and grabbed ownership using USB? Ethernet is normally picked up early in the boot process, USB much later - though I don't offhand know at what stage in the boot the VM would claim ownership.

I notice that the first Ethernet card has an APIPA address, so the VM found no DHCP there. The second configured card seems to have a valid LAN address.

[bobptz]

Hello

@mpack, I never used a USB WiFi dongle


@socratis:

Yes, all my Guests are attached to "Bridged adapter".

Here is a list of the MAC addresses:

Host0 (connected with cable):
i5-ubuntu mac address: d050994b7ab7 IP detected: 192.168.1.109
Guest0:
i5-w7 mac address: 0800276FE7D5 IP detected: 192.168.1.124

Host1 (connected with cable AND wifi):
i5-dell-(enp0s25) mac address: 848F69F1722F IP detected: 192.168.1.106
i5-dell-(wlp8s0) mac address: 0811968F4210 IP detected: 192.168.1.107
Guest1 (obtained by VB network settings):
i5-dell-w7-(enp0s25) mac address: 080027BF7D0E
i5-dell-w7-(wlp8s0) mac address: 080027421EDA
Guest1 (obtained by ipconfig /all):
Ethernet adapter wired mac address: 08-00-27-42-1E-DA IP detected: 192.168.1.105
Ethernet adapter wifi mac address: 08-00-27-BF-7D-0E IP detected: 192.168.1.135

Please notice above that guest1 -> i5-dell-w7-(wlp8s0) (which I understand connects to the Host's wifi) has the same MAC as the Guest1 -> Ethernet adapter wired. This is what I meant by "inverted" MAC addresses.


Host2 (connected with wifi):
I7-DELL (eno1) mac address: E0DB55EADDF4 IP detected:
I7-DELL (wlp2s0) mac address: 843A4B2206C4 IP detected: 192.168.1.100
Guest2 (obtained by VB network settings):
I7-DELL-W7 (eno1) mac address: 0811968F4210
I7-DELL-W7 (wlp2s0) mac address: 08002741A42F
Guest2 (obtained by ipconfig /all):
Ethernet adapter wired mac address: 08-00-27-41-A4-2F IP detected: 192.168.1.145
Ethernet adapter wifi mac address: 08-11-96-8F-42-10 IP detected:

Guest1 and Guest2 report a conflict in the IP addresses. Guest0 never complained.


This is the output of ipconfig /all from Guest1:

Code: Select all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : I5-Dell-win7
   Primary Dns Suffix  . . . . . . . : 
   Node Type . . . . . . . . . . . . : Broadcast
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : lan

Ethernet adapter wired:

   Connection-specific DNS Suffix  . : lan
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter #2
   Physical Address. . . . . . . . . : 08-00-27-42-1E-DA
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2a02:587:4c1a:fc00::666(Preferred) 
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 18:59:19
   Lease Expires . . . . . . . . . . : ТЬлсилЮ, 27 ЛШилхжм 2019 12:47:16
   IPv6 Address. . . . . . . . . . . : 2a02:587:4c1a:fc00:8da1:db55:5eda:628c(Preferred) 
   IPv6 Address. . . . . . . . . . . : fdf7:1a7c:a459::666(Preferred) 
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 18:59:20
   Lease Expires . . . . . . . . . . : СсЩЩШлж, 3 ЛШ?жм 2155 01:29:36
   IPv6 Address. . . . . . . . . . . : fdf7:1a7c:a459:0:8da1:db55:5eda:628c(Preferred) 
   Temporary IPv6 Address. . . . . . : 2a02:587:4c1a:fc00:b199:caf0:fda7:1b41(Preferred) 
   Temporary IPv6 Address. . . . . . : fdf7:1a7c:a459:0:b199:caf0:fda7:1b41(Preferred) 
   Link-local IPv6 Address . . . . . : fe80::8da1:db55:5eda:628c%15(Preferred) 
   IPv4 Address. . . . . . . . . . . : 192.168.1.105(Preferred) 
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 17:35:04
   Lease Expires . . . . . . . . . . : ТЬлсилЮ, 27 ЛШилхжм 2019 17:35:04
   Default Gateway . . . . . . . . . : fe80::16cc:20ff:feba:5d2a%15
                                       192.168.1.2
   DHCP Server . . . . . . . . . . . : 192.168.1.2
   DHCPv6 IAID . . . . . . . . . . . : 369623079
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1A-BA-87-03-08-00-27-6F-E7-D5
   DNS Servers . . . . . . . . . . . : fdf7:1a7c:a459::1
                                       192.168.1.2
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter wifi:

   Connection-specific DNS Suffix  . : lan
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter
   Physical Address. . . . . . . . . : 08-00-27-BF-7D-0E
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2a02:587:4c1a:fc00::23a(Preferred) 
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 18:59:22
   Lease Expires . . . . . . . . . . : ТЬлсилЮ, 27 ЛШилхжм 2019 12:47:16
   IPv6 Address. . . . . . . . . . . : 2a02:587:4c1a:fc00:68a3:e570:da07:493(Preferred) 
   IPv6 Address. . . . . . . . . . . : fdf7:1a7c:a459::23a(Preferred) 
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 18:59:23
   Lease Expires . . . . . . . . . . : СсЩЩШлж, 3 ЛШ?жм 2155 01:29:36
   IPv6 Address. . . . . . . . . . . : fdf7:1a7c:a459:0:68a3:e570:da07:493(Preferred) 
   IPv6 Address. . . . . . . . . . . : 2a02:587:4c1a:fc00::a3f(Duplicate) 
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 18:10:50
   Lease Expires . . . . . . . . . . : ТЬлсилЮ, 27 ЛШилхжм 2019 12:47:17
   Temporary IPv6 Address. . . . . . : 2a02:587:4c1a:fc00:5116:b47:f51c:9a7b(Preferred) 
   Temporary IPv6 Address. . . . . . : fdf7:1a7c:a459:0:5116:b47:f51c:9a7b(Preferred) 
   Link-local IPv6 Address . . . . . : fe80::68a3:e570:da07:493%14(Preferred) 
   IPv4 Address. . . . . . . . . . . : 192.168.1.135(Preferred) 
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 17:27:03
   Lease Expires . . . . . . . . . . : ТЬлсилЮ, 27 ЛШилхжм 2019 17:27:03
   Default Gateway . . . . . . . . . : fe80::16cc:20ff:feba:5d2a%14
                                       192.168.1.2
   DHCP Server . . . . . . . . . . . : 192.168.1.2
   DHCPv6 IAID . . . . . . . . . . . : 319291431
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1A-BA-87-03-08-00-27-6F-E7-D5
   DNS Servers . . . . . . . . . . . : fdf7:1a7c:a459::1
                                       192.168.1.2
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Local Area Connection* 11:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : 
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.lan:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : lan
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

This is the output of ipconfig /all from Guest2:

Code: Select all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : I7-Dell-win7
   Primary Dns Suffix  . . . . . . . : 
   Node Type . . . . . . . . . . . . : Broadcast
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : lan

Ethernet adapter wired:

   Connection-specific DNS Suffix  . : lan
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter #2
   Physical Address. . . . . . . . . : 08-00-27-41-A4-2F
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2a02:587:4c1a:fc00:54e2:4ebe:3d85:f52b(Preferred) 
   IPv6 Address. . . . . . . . . . . : fdf7:1a7c:a459:0:54e2:4ebe:3d85:f52b(Preferred) 
   Temporary IPv6 Address. . . . . . : 2a02:587:4c1a:fc00:5d54:c4aa:28d7:3a8b(Preferred) 
   Temporary IPv6 Address. . . . . . : fdf7:1a7c:a459:0:5d54:c4aa:28d7:3a8b(Preferred) 
   Link-local IPv6 Address . . . . . : fe80::54e2:4ebe:3d85:f52b%15(Preferred) 
   IPv4 Address. . . . . . . . . . . : 192.168.1.145(Preferred) 
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : ТихлЮ, 26 ЛШилхжм 2019 17:02:27
   Lease Expires . . . . . . . . . . : ТЬлсилЮ, 27 ЛШилхжм 2019 17:02:41
   Default Gateway . . . . . . . . . : fe80::16cc:20ff:feba:5d2a%15
                                       192.168.1.2
   DHCP Server . . . . . . . . . . . : 192.168.1.2
   DHCPv6 IAID . . . . . . . . . . . : 369623079
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1A-BA-87-03-08-00-27-6F-E7-D5
   DNS Servers . . . . . . . . . . . : fdf7:1a7c:a459::1
                                       192.168.1.2
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter wifi:

   Connection-specific DNS Suffix  . : 
   Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter
   Physical Address. . . . . . . . . : 08-11-96-8F-42-10
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::95a0:8c6d:38de:97ff%14(Preferred) 
   Autoconfiguration IPv4 Address. . : 169.254.151.255(Preferred) 
   Subnet Mask . . . . . . . . . . . : 255.255.0.0
   Default Gateway . . . . . . . . . : 
   DHCPv6 IAID . . . . . . . . . . . : 319291431
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1A-BA-87-03-08-00-27-6F-E7-D5
   DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
                                       fec0:0:0:ffff::2%1
                                       fec0:0:0:ffff::3%1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.lan:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : lan
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : 
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.{DC08AC1B-5A2A-4F36-AC81-D94E62737EC1}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : 
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

You will notice above :

Code: Select all

Ethernet adapter wired:
   Physical Address. . . . . . . . . : 08-00-27-41-A4-2F
   IPv4 Address. . . . . . . . . . . : 192.168.1.145(Preferred)

But Host2 is connected with WiFi, not cable.

[bobptz]

I just noticed an IP conflict message on Guest0 too. So all 3 guests have problem.

[bobptz]

I found the duplicate MAC addresses:

HOST1: i5-dell-(wlp8s0) mac address: 0811968F4210
GUEST2: I7-DELL-W7 (eno1) mac address: 0811968F4210

Jesus, what is the probability for this one?

I hope not to have conflict after changing those.

Do you have any idea why I have this "inverted" mac addresses?

[bobptz]

Unfortunately the problem remains, even after making all MACs unique. After about 10 minutes of starting all 3 VMs, all of them complained of duplicate IPs.

Code: Select all

Host0 (connected with cable):		
i5-ubuntu	mac address:	d050994b7ab7
Guest0:		
i5-w7	mac address:	0800276FE7D5
		
Host1 (connected with cable AND wifi):		
i5-dell-(enp0s25)	mac address:	848F69F1722F
i5-dell-(wlp8s0)	mac address:	0811968F4210
Guest1 (obtained by VB network settings):		
i5-dell-w7-(enp0s25)	mac address:	080027BF7D0E
i5-dell-w7-(wlp8s0)	mac address:	080027421EDA
Guest1 (obtained by ipconfig /all):		
Ethernet adapter wired	mac address:	08-00-27-42-1E-DA
Ethernet adapter wifi	mac address:	08-00-27-BF-7D-0E
		
Host2 (connected with wifi):		
I7-DELL (eno1)	mac address:	E0DB55EADDF4
I7-DELL (wlp2s0)	mac address:	843A4B2206C4
Guest2 (obtained by VB network settings):		
I7-DELL-W7 (eno1)	mac address:	080027783497
I7-DELL-W7 (wlp2s0)	mac address:	08002741A42F
Guest2 (obtained by ipconfig /all):		
Ethernet adapter wired	mac address:	08-00-27-41-A4-2F
Ethernet adapter wifi	mac address:	08-00-27-78-34-97

Any other ideas?

[bobptz]

I tried to renew the IP addresses in all 3 guests:

Code: Select all

ipconfig /release
ipconfig /renew

The problem remains.

[andyp73]

Now that you have got all of the MAC addresses to be unique you need to look further across your network. Is there a DHCP server that might be giving out dynamic IP addresses and one conflicts with a device that has a static IP address?

The warnings from the operating system should tell you which IP address it is that is in conflict. Use that to find where it is.

-Andy.