IP Address Conflict

I am using a linksys wrt54gs router, a wre54g range expander and a wusb200 wireless adapter, there is only one computer on the network and it's set to a static IP address. Could someone please explain to me how I'm getting an IP address conflict with another system on the network?
Please?
I've already been through linksys phone support.
Twice.

Please list all the static LAN IP addresses that you are using on your network. Also, if you are not using the default DHCP server range of 192.168.1.100 thru 192.168.1.149 , then please state your DHCP server range.
Is your WRE54G, using the default fixed LAN IP address of 192.168.1.240 ?
Assuming that your addresses are all correct, then the next most likely cause for your problem is that your computer is connecting both to your router, and to your WRE54G, and the WRE54G is in turn forwarding the connection to the router. The router sees the direct connection and the connection through the WRE54G and interprets this as two connections with the same LAN IP address.
If this is the case, I would suggest that you try to eliminate the WRE54G. It sounds like your wireless computer can connect directly to your router. If you can connect, but not well, use the HGA7T high gain antennas on your WRT54GS, instead of the WRE54G.
A third way to get an address conflict is if your neighbor has set his computer to a fixed LAN IP address, and he is also connecting to your network. In this case, secure your wireless network.
Message Edited by toomanydonuts on 12-10-2007 09:04 PM

Similar Messages

Windows 8.1 Hyper-V : IP address conflict on Guest OS

Hi ,
I have just installed Windows 8.1 and I want to move away from VMWare Player and use Hyper-V instead.
I have nevertheless issues with it on the networking side.
Before setting up my VM, I have:
- converted my vmdk to a vhd.
- created a virtual switch in Hyper-V Manager.
After that, i created the VM using the vhd and the virtual switch created beforehand.
Once I boot up the guest OS (Windows 7), I have no internet connectivity on the guest OS, and it says : windows has detected an IP address conflict
Also when I run ipconfig in a command prompt on the guest, I can see an ip address which is the same as my host OS (192.168.1.5) but then I guess that my host system takes the IP back as if i run ipconfig again the IP address is gone.
So I guess that my host and guest OS fight for the same IP. Also the message "windows has detected an IP address conflict" appears on the Guest OS.
Also at times, the guest OS receive a strange IP: 169.254.99.175 which I have no clue where it comes from.
Does anyone has an idea on how to solve the issue?
Also here is a screenshot of the configuration of the Virtual Switch :
Thanks for any help,
Francois

Hi Dan,
I guess that you use IP address reservation on your router (configuring your router so that DHCP always gives the same IP address for a particular MAC address).
As both your virtual machines and host machine will appear on the network as having the same MAC address, they will both get assigned the same IP by the router.
The solution is to turn off IP Address reservation. Another option is to assign a fixed IP instead of using DHCP.
I now here have 3 VMs on my Windows 8 machine, some use fixed IP and some use DHCP and they all work fine. The important part is to make sure your router does not have settings to assign a particular IP for a particular MAC address.
Good luck!
Francois
Thanks. Reservation is not configured in the router - I have the option of specifying a MAC address and assigning an IP, but the table is blank. I'm guessing it mayb defaults to it? It's a router from the local ISP.
In the advanced option of the virtual adapter in Hyper VM, I selected a static MAC. For whatever reason, the VM now has it's own IP address, X.X.X.7. Host is X.X.X.3
2 strange things though.
1. I can only access the router config page (X.X.X.1) via the VM. On the host, each time I try to login, it kicks me out. It's a Cox branded Netgear router (from ISP). Once I shutdown the VM, I can access the router config page on the host.
2. When looking at the list of connected clients in the router, it only shows the Machine name for the host - however, the corresponding IP address shown is that of the VM.
Weird ...
Anyway, not so concerned with having it work at home - it will be more so for at work.

IP address conflict - pls help...

Hi
I get on my iMac (and also on the MacBook) sometimes the message: *Another device on the network is using your computer's IP address (10.0.0.8).* After a view seconds (and evidently a change of the IP address) Ethernet connectivity works again. When does this happen: e.g. after waking up the Laptop from sleep modus.
Here is my setup:
. ADSL router with 10.0.0.138 GW address
. all devices directly connected via a Gigabit switch
. most devices are set to DHCP except one
. one device needs to have a manual set IP address (set now to 10.0.0.180), because it does not support DHCP (is a special HW for the solar system)
. devices connected via Ethernet cable include:
          - iMac DHCP
          - Windows PC DHCP
          - Apple Time Capsule DHCP
          - PS3 DHCP
          - TV Samsung LED DHCP
          - SAT Receiver Sky+ DHCP
          - NAS DHCP
           - Fronius Data Logger static IP 10.0.0.180
. devices connected via WLAN (to Apple Time Capsule) all using DHCP
          - Apple TV
          - Wii
          - iPhone 4
          - 2 iPads
          - Samsung mobile phone
          - MacBook
All have DCHP activated.
I dont understand how a device can get the same IP address from the DHCP and so causing an IP address conflict. Unless, there are 2 active, which I did not yet figure out...
What did I change lately (before this change, I did not have this problem)?
. I had another router behind the ADSL router, set to 192.168.0.x internal address range for the home network. It got broke so I took it out of the setup as the new ADSL router anyway has a firewall. Since then I have these issues.
What does "got broke" mean - as I am not sure whether this helps in finding the root cause: what happened is that after our vacation when I switched on all clients again I could surf the Internet lets say for 1hour or so and then suddenly all clients lost connection and had an 169.254.0.x IP address. And this although DCHP IP address lifetime of the router was set to 24h and the actual lifetime of the clients IP addresses where in that range (as I reseted the router). Before our vacation all was fine. BTW, the ADSL router works fine (I use also IPTV service over it and it works perfectly all the time).
So before that change, I had a private network segment with 192.168.0.x extending from the router to all wireline devices. I am not sure, but it can be that the Time Capsule, i.e. the wireless network, was on 10.0.0.x (I dont know). Then things would be clear to me, as then evidently the Time Capsule runs a separte DHCP from which the wireless devices fetch their IP address and if they are now all in the same network segment (both wireless and wireline)...then "Houston we have a problem":)
So my questions are:
. is the Airport setting of the Time Capsule wrong? I used "create a wireless network". Is it now just extending the 10.0.0.x network to the wireless domain? Hence do the wireless clients fetch their IP addresses from the ADSL router or the Time Capsule?
. Is the wireless and wireline network fully transparent, can wireless devices connect without problems to a wireline device (e.g. the MacBook to the NAS)?
. Is there an app that helps to identify the clients? I can get from my router a list of IP addresses used by clients, but I cannot link them to the devices.
BR
a

https://discussions.apple.com/message/15887700#15887700
I am having a similar issue as described in another post. search "Time Capsule IP address Conflict".   This is a relatively large home network with a number of media devices, PCs and Macs on a network behind and ATT uverse 2wir router.
Everything worked fine until I added the Time Capsule to the network. Initially the TC got an IP address frou the 2wire router and all was fine.   But the next day I recieved and IP addres conflict from a Mac Book.
TC is Bridge mode - Wireless turned off - attached diretly to a lan port on the 2wire router.
It looked like the TC recieved an IP address from the 2wire router but the 2wire indicated that it was a static IP, rather than one being issued by DHCP. The 2wire handed out the same address to the Mac Book.
I shut down the TC and the Mac Book, rebooted the TC and Mac Book. Everything seemd to be fine. This time the TC got an address from the 2wire DHCP pool 192.168.1.113.   This gave me the opportunity to reserve the address hoping that the TC would get this address every time, and keep it from being handed out to another device.
Everything seemed fine for a day.
Next day we get another address conflict.
The airport utility on an Imac still says that the TC is 192.168.1.113 but the 2wire router does not show the .113 address. Instead it says that the TC has a static IP of .117 .
The Mac Book shows an address of .117.
Shut down the TC
Shut Down the Mac Book
Reboot the Mac Book and Manually assign .120
Change the Macbook to get DHCP address.   It now Gets .120    I reserve .120 for the mac Book
Reboot the TC
It gets .113 and shows up on the 2wire router as .113 issued from DHCP.
Reserver .113 for the TC again.
Waiting to see what happens.
Does the TC go to sleep?
If so does it lose its IP assignment and get a new one when it wakes up?
While it's asleep does DHCP try to give its address to another device?
I would be tempted to blame the DHCP service in the 2wire router accept everything works fine when the TC is not on the network.

IP Address Conflict Using Mobile Hotspot On Iphone 5

Hello,
I just got my new Iphone 5 and I love it, apart from one little problem. Now when I connect it to my laptop using the mobile hotspot (either via usb or wireless) I am constantly getting a network error popup stating that there is an ip address conflict.
Hardware info:
Iphone 5 16gb
Asus G74S Laptop with Windows 7 64bit
Error info:
The error popup is in the form of a small window titled Network Error. It states "Windows has detected an IP address conflict" "Another computer on this network has the same IP address as this computer... blah blah blah"
The windows system event viewer has the following log:
Source is Tcpip
The system detected an address conflict for IP address :: with the system having network hardware address 00-00-00-00-00-00. Network operations on this system may be disrupted as a result.
The event ID is 4199
Done so far:
Already did every single troubleshooting step in regards to ip address conflicts, ipconfig /release and /renew, flush dns etc. I even did an entire system restore on my laptop back to factory settings. Installed a fresh Itunes 10.7 64bit and reconnected my new Iphone 5 and am still getting this message. I never had this problem with my Iphone 4.
Called Apple tech support, they ran me through all the steps relating to the phone itself, reseting network settings, resetting factory settings, removing and re-inserting the sim card, you name it.
Disabled IPv6 in the registry and reboot, still the same popup occurs.
Tried to assign a static IP address to Ipv4, still the same popup
Any ideas?

Still having the same issue....Is there another thread in which this is resolved? Iphone 5, IOS 6. It's just the phone tethered to a laptop (have tried with two laptops, both get the ip address conflict error, so the problem resides in the phone). No other devices are on the network. Was this ever addressed?
We use the iphone 5 as a mobile hotspot for our business, which is completely internet/skype based, and we need to be mobile. Mifi keeps kicking off the connection, so they are not an option. Thank you.

IP Address Conflict with range expander

Hi,
I have a Linksys WRT610N router that I am trying to extend the range of using a Hawking HWREN1. The router configures fine and I'm able to access the Internet from an attached PC. When I hook up the Hawking extender, it configures correctly, it seems, but as soon as it saves the configuration, Windows XP on the PC tells me that there is an IP address conflict.
Hawking suggested a factory reset of the extender and redoing setup, which I did, with no success. As soon as I unplug power to the extender, the error goes away, so the issue is connected to the extender.
I've also tried using a completely different IP address range, setting the router to 192.168.2.2. The PC is set to 192.168.2.201, and the extender to 192.168.2.202, and still I get the IP address error message.
I'm unsure how to perform further diagnostics on this, since at least from the looks of things, there is no IP address conflict, even tho the error message says that there is. Is there something else that could cause an IP address conflict besides the IP address itself, for example? BTW, the extender was purchased on advice of a store clerk, who said that they'd had good luck with the Hawkings. Is there a more appropriate product to use from Linksys. Supposedly, the Hawking is better because it covers a larger variety of standards, even tho it is not dual band like the router. I haven't seen any dual band extenders around.
Any help would be appreciated.
Thanks.
Ron
Solved!
Go to Solution.

If you are getting these error mesasge on your Computer, these means your Both the computers are getting the same IP address from the Router. To avoide getting these error message, you can assigne a Static IP to your Hardwired Computer.
On your XP computer follow the settings bellow. Click on the Start button >>> Settings >>> Control Panel >>>Network Connections- Right click on the icon for Local area connection and go to properties- On the 'General' tab select 'Internet Protocol TCP/IP' and click on the Properties button- Select 'Use the following IP address'- Provide IP Address - 192.168.1.5, Subnet Mask - 255.255.255.0, Default Gateway - 192.168.1.1- Preferred DNS 192.168.1.1, Alternate DNS - 4.2.2.2 >>Click on Ok button to Save and Click on "Close" on main Properties window.
Now check if you are Online from your computer, and i think these should solve your Problem.

When syncing my iphone 6 plus, i now get an error that reads, "IP address conflicts with another system or network." How can i eliminate this error permanently? Thank you in advance!

when syncing my iphone 6 plus, i now get an error that reads, "IP address conflicts with another system or network." How can i eliminate this error permanently? Thank you in advance!
This never happened before, however the last couple of months it comes up every time I plug my USB from PC to iphone.

HyperNova Software,
Thank you so much. Because I am very computer illiterate, could you help me on how to get started? I don't have the slightest on where to get started, the steps to follow, etc.
Can't thank you enough for your help!

WRT54G IP Address conflict...

After 3 sessions with Linksys live chat I have done everything suggested and nothing has worked. Here is the situation:
the router(WRT54G v.3 firmware 4.21.1) is working. I can connect to the internet through the router with my notebook(Windows XP Home SP2) using both wired and wireless connection. IP Addresses are:
wireless -- 192.168.1.101
wired -- 192.168.1.102
I can connect to the internet through the router with a second desktop (Windows XP Home SP2) using wired connection. IP Address is:
wired -- 192.168.1.103
I can NOT connect to the internet through the router using my primary desktop(Windows Vista Home Premium SP1). What I have discovered by checking the windows event log, is this:
The system detected an address conflict for IP address 75:65:84:74 with the system having network hardware address 00-13-10-94-A3-17. Network operations on this system may be disrupted as a result.
Here is the result of ipconfig /all: (with router OUT of the system)
Windows IP Configuration
Host Name . . . . . . . . . . . . : AlBateman-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . :Hybrid
IP Routing Enabled. . . . . . . . :No
WINS Proxy Enabled. . . . . . . . :No
DNS Suffix Search List. . . . . . :hsd1.la.comcast.net.
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . : hsd1.la.comcast.net.
Description . . . . . . . . . . .: NVIDIA nForce Networking Controller
Physical Address. . . . . . . . . : 00-1E-90-69-12-D5 - this is now the correct address
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::b8fd:96ff:164e:395a%16
IPv4 Address. . . . . . . . . . . : 75.65.78.130 -- I assume this is being assigned by comcast
Subnet Mask . . . . . . . . . . . : 255.255.252.0
Lease Obtained. . . . . . . . . . : Sunday, September 14, 2008 4:18:35 PM
Lease Expires . . . . . . . . . . : Thursday, September 18, 2008 4:18:35 PM
Default Gateway . . . . . . . . . : 75.65.76.1
DHCP Server . . . . . . . . . . . : 68.87.68.16
DNS Servers . . . . . . . . . . . : 68.87.68.162
68.87.74.162
68.87.64.196
NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter Local Area Connection* 6:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 02-00-54-55-4E-01
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Local Area Connection* 9:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : hsd1.la.comcast.net.
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* 15:
Connection-specific DNS Suffix . : hsd1.la.comcast.net.
Description . . . . . . . . . . .: Microsoft 6to4 Adapter
Physical Address. . . . . . . . .: 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . .: No
Autoconfiguration Enabled . . . .: Yes
IPv6 Address. . . . . . . . . . .: 2002:4b41:4e82::4b41:4e82(Preferred)
Default Gateway . . . . . . . . .: 2002:c058:6301::c058:6301
DNS Servers . . . . . . . . . . .: 68.87.68.162
68.87.74.162
68.87.64.196
NetBIOS over Tcpip. . . . . . . .: Disabled
The router is currently reset to factory settings:
Internet setup
Internet Connection Type Automatic Configuration-DHCP
Optional Settings (required by some ISPs)
Router Name: WRT54G
Host Name:
Domain Name:
MTU:
Auto Size: 1500
Network Setup
Router IP
Local IP Address: 192.168.1.1
Subnet Mask: 255.255.255.0
Network Address
Server Settings (DHCP)
DHCP Server: Enable
Starting IP Address: 192.168.1.100
Maximum Number of DHCP Users: 50
Client Lease Time: 0 minutes (0 means one day)
Static DNS 1: 0.0.0.0
Static DNS 2: 0.0.0.0
Static DNS 3: 0.0.0.0
WINS: 0.0.0.0
Time Setting Time Zone: (GMT-08:00) Pacific Time (USA & Canada)
MAC Clone Enabled
User Defined Entry: 00-1E-90-69-12-D5
Router Information
Firmware Version: v4.21.1, Nov. 6, 2006
Current Time: Not Available
MAC Address: 00-1E-90-69-12-D5
Router Name: WRT54G
Host Name:
Domain Name:
Internet
Configuration Type
Login Type: Automatic Configuration - DHCP
IP Address: 0.0.0.0
Subnet Mask: 0.0.0.0
Default Gateway: 0.0.0.0
DNS 1:
DNS 2:
DNS 3:
MTU: 1500
The ONLY change made to the default settings was to click on MAC Clone.
WITH THE ROUTER CONNECTED:
Status: Router:
Firmware Version: v4.21.1, Nov. 6, 2006
Current Time: Sun, 14 Sep 2008 16:41:33
MAC Address: 00-1E-90-69-12-D5
Router Name: WRT54G
Host Name:
Domain Name: hsd1.la.comcast.net.
Internet
Configuration Type
Login Type: Automatic Configuration - DHCP
IP Address: 75.65.78.130
Subnet Mask: 255.255.252.0
Default Gateway: 75.65.76.1
DNS 1: 68.87.68.162
DNS 2: 68.87.74.162
DNS 3: 68.87.64.196
MTU: 1500
Status: Local Network:
MAC Address: 00:13:10:94:A3:17
IP Address: 192.168.1.1
Subnet Mask: 255.255.255.0
DHCP Server: Enabled
Start IP Address: 192.168.1.100
End IP Address: 192.168.1.149
netstat -rn
=================================================================
Interface List
16 ...00 1e 90 69 12 d5 ...... NVIDIA nForce Networking Controller
1 ........................... Software Loopback Interface 1
8 ...02 00 54 55 4e 01 ...... Teredo Tunneling Pseudo-Interface
18 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
19 ...00 00 00 00 00 00 00 e0 6TO4 Adapter
=================================================================
IPv4 Route Table
=================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 75.65.76.1 75.65.78.130 20
75.65.76.0 255.255.252.0 On-link 75.65.78.130 276
75.65.78.130 255.255.255.255 On-link 75.65.78.130 276
75.65.79.255 255.255.255.255 On-link 75.65.78.130 276
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 75.65.78.130 276
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 75.65.78.130 276
=================================================================
Persistent Routes:
None
IPv6 Route Table
=================================================================
Active Routes:
If Metric Network Destination Gateway
19 1125 ::/0 2002:c058:6301::c058:6301
1 306 ::1/128 On-link
19 1025 2002::/16 On-link
19 281 2002:4b41:4e82::4b41:4e82/128
On-link
16 276 fe80::/64 On-link
16 276 fe80::b8fd:96ff:164e:395a/128
On-link
1 306 ff00::/8 On-link
16 276 ff00::/8 On-link
=================================================================
Persistent Routes:
None
> In addition, please post the "ipconfig /all" output of the
> computer which does not work correctly in the full setup,
> i.e.computer wired to the router, router wired to the modem,
> router has a working internet connection. Add the output of
> "netstat -rn".
The router does NOT have a working internet connection when connected to that particular pc.
SO... how do I fix this conflict with IP Addresses? All of the resetting & powering off & on & etc.... hasn't changed anything.
Message Edited by BatBytes on 09-15-2008 11:09 AM

Here are ipconfig /all & netstat -rn with complete hookup:
ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : AlBateman-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : NVIDIA nForce Networking Controller
Physical Address. . . . . . . . . : 00-1E-90-69-12-D5
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::b8fd:96ff:164e:395a%16(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :
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 Local Area Connection* 6:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 02-00-54-55-4E-01
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Local Area Connection* 15:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : 6TO4 Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Local Area Connection* 16:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
netstat -rn
===========================================================================
Interface List
16 ...00 1e 90 69 12 d5 ...... NVIDIA nForce Networking Controller
1 ........................... Software Loopback Interface 1
8 ...02 00 54 55 4e 01 ...... Teredo Tunneling Pseudo-Interface
19 ...00 00 00 00 00 00 00 e0 6TO4 Adapter
24 ...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
===========================================================================
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
192.168.1.0 255.255.255.0 On-link 192.168.1.100 276
192.168.1.100 255.255.255.255 On-link 192.168.1.100 276
192.168.1.255 255.255.255.255 On-link 192.168.1.100 276
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 192.168.1.100 276
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 192.168.1.100 276
===========================================================================
Persistent Routes:
None
IPv6 Route Table
===========================================================================
Active Routes:
If Metric Network Destination Gateway
1 306 ::1/128 On-link
16 276 fe80::/64 On-link
16 276 fe80::b8fd:96ff:164e:395a/128
On-link
1 306 ff00::/8 On-link
16 276 ff00::/8 On-link
===========================================================================
Persistent Routes:
None

The (in)famous IP address conflict...

Hi all
I have a linksys befw11s4, which seems to be working fine - the only problem is that every week or so, when more than two computers (or smart phones) try to connect I get the "IP Address conflict" or two devices with the same IP address or " Wireless network connection doesn't have a valid IP configuration" ... there are thousands of similar posts on the internet, many with extremely difficult and complicated answers which seems not to work. This problem happens with computes/devices trying to connect thru wireless or thru lan cable. I tried fixing this so many times I don;t even remember when I started... I am extremely frustrated!!!
Is there any simple, one time solution? Upgrade? Software patch?
To me this seems crucial and very, very basic problem - if people at the end cannot connect, then all other features are worthless. It's like buying a new car which has a built in coffee maker and an excellent entertainment system but the engine will not start....
Hope anyone has some insights....

Though a manual IP address on any device can cause this, another common cause is this:
Your Linksys router probably has factory-default wireless settings and it's in-rage of a neighbor's wireless router with the same settings. Both routers see traffic that wasn't meant for it, and the wireless networks are "merged" in a way that causes IP conflicts.
SSID: linksys
Channel: 6
Security: none
...if these are your wireless settings, then this is probably the cause of your IP conflicts. You won't necessarily see two "linksys" networks when you look at wireless networks in-range.
Your router assigns local IPs to your devices starting with 192.168.1.100, ...101, ...102, ...103, etc. Each device on your LAN (local network) gets a slightly different IP address. Your neighbor's router does the same, also starting with 192.168.1.100. When your router sees traffic that wasn't meant for it, it's extremely likely both of you have a device with the .100 address, and both of you will experience a conflict. If both of you have more than one device, you may also get conflicts from .101, .102, etc.
The popularity of Linksys-brand products makes this a common issue. However, I've had similar problems with Netgear, D-Link, and Belkin products. For a long time, the devices didn't have a unique SSID from the factory. It also would have made sense for each one to default to a setting that selects a random channel after every reboot (or scans and selects one with the least interference).
The solution is easy. Change the name and channel of your wireless network. That's also a good opportunity to enable WPA-Personal or WPA-PSK encryption and set a wireless password ("key" or "passphrase"). Make sure you use a wired connection when changing any wireless settings, or your computer can get VERY confused. Also keep in mind that your configuration password isn't the same thing as a wireless password. I would recommend writing down any passwords and keys on a sticky note and put it under your router. Usually, you want your household and guests to access this information, but strangers and neighbors won't be able to use your network without that information.
The merged networks present an unusual challenge. In the past, I have attempted to change the wireless settings by logging-in to the router's web configuration from a wired computer with no wireless capability. I rebooted the router and loaded the web configuration page at http://192.168.1.1/, then promptly changed the network name and channel. It turns out that traffic was already merged with the neighbor's router. Even though I used a wired connection, my changes were applied to the neighbor's router! My router still had an SSID of "linksys" and the neighbor's had the new SSID. The wireless networks were no longer merged because the SSIDs were now different, so I rebooted the router one more time and made my changes (making sure to use a *slightly* different SSID than the one that was applied to the neighbor's router). I used another wireless-capable computer to connect to the neighbor's wireless and undo those accidental changes.

IP address conflict on Windows 7 clients after change 3560 to 3650

Hi,
after a switch change 3560 to 3650 some Windows 7 clients show a popup with the message "IP address conflict". Because of using manual DHCP (MAC reserve an IP address) i would exclude the possibilitiy of using an duplicate IP address. After search i found this document:
http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/8021x/116529-problemsolution-product-00.html
I tried the command
ip device tracking probe delay 10
on the 3650 sw. Till now there are no messages with duplicate IP addresses on clients which connected to 3650 sw.
But on on 3560 sw th command does not exist. Anybody who has a similar problem or an idea to solve the problem on the 3560 sw.
The command "sh ip device tracking all" on 3560 shows that ip device tracking is disabled.
Thx for any help.

IOS version 12.2.(46) SE
the suggested command does not exist.
btw the ip address conflict popup appears on clients which are connect to the 3560 too.
any other ideas?

160N IP address conflict

My new 160N is connected to desktop (hard-wired) and then wireless to laptop. Strangely, I lose internet connection on desktop while computers both see each other and laptop continues to have internet connection. When I lose desktop internet I get message about IP address conflict.
I have current firmware and reset router several times. I have IP address set to auto. Range is excellent on router. I'm running Vista.

Kevj (below) solved my problem. Downgrading from build 11 to build 8 is the answer. It's unbelievable that the techies I called at Linksys didn't tell me to try it. They finally told me to return defective router. Linksys could have saved all their time, my aggravation and countless returned routers. Mine was ready to be returned - Had the RMA no. and box ready. Everything running great now.

Airport Extreme Base Station and DSL modem, IP address Conflict issues

I recently set up DSL service in my apartment. I have ATT yahoo DSL modem, and an Airport extreme base station plugged into it. The network works fine with my Vista PC connected to it, but when I try to connect my macbook to the network I get errors telling me the IP address the macbook wants to use is already in use, and my PC gives me an IP address conflict error.
The internet is fine, and the modem is configured automatically, so I think it must be a problem with the way the network is set up or the network settings on my macbook...
any ideas?

All,
I recently posted what I believe to be a similar/identical issue. See my post here: http://discussions.apple.com/thread.jspa?threadID=1378849
I have not changed my AEBS to "Off (Bridge Mode)" yet, because everything currently 'works' but I continue to get the occasional "Double NAT" warning suggesting I switch the AEBS to bridge mode. When this happens, I lose connection to the internet and need to unplugged both the AEBS and my modem to re-establish a connection to the internet and the external HD I have connected to the AEBS.
My question for Jmiller1138, do you continue to get the "Double NAT" warning even when you changed your AEBS to "Off (Bridge Mode)"? I am hesitant to change my AEBS to bridge mode since I'm assuming I'll need to totally reconfigure my entire network (meaning both the AirPort Extremes, my wireless HP printer, and my firewalls on my PCs).
The ignoring of the warning (i.e. closing the AirPort Utility without updating the AEBS) is what triggers the need to reset my AEBS and modem. Not fun.
I guess I'll just need to bite the bullet and set the AEBS to bridge mode . . . yes?

IP address conflict help and setting up security code for access

Hi folks, I am about as non-technical as one can get. So I apologize in advance and thank you guys for your patience as everything you tell me will have to be spelled out for me.
Ques 1: I have one desk top computer with internet access through my cable TV provider. On it I have the Linksys WRT54G wireless router. We use two laptops.
Lately I've been getting an error message on my desktop saying there is an IP Address that is in conflict. My son often gets booted off line (on laptop) and so I'm guessing maybe it is his laptop that is in conflict. Please help me resolve this issue.
Quest 2: I would like to set up a security code for our wireless access so that other people will not be able to intrude upon our signal. Can someone walk me through this as well?
Thank you so much!
-Jen in NJ

The most common reason to get two identical IP addresses, is if you are using fixed LAN IP addresses incorrectly on your system.
Do you already use any fixed LAN IP addresses? If so, please state what fixed LAN IP addresses you are using, and also state your DHCP server range.
Rules for using fixed LAN IP addresses on Linksys routers:
With Linksys routers, a fixed (static) LAN IP addresses must be assigned in the device that is using the address. So you need to enter the fixed address in the computer or printer, not in the router.
When using a Linksys router, any fixed LAN IP address must be outside the DHCP server range (typically 192.168.1.100 thru 192.168.1.149), and it cannot end in 0, 1, or 255.
Therefore any fixed LAN IP address would normally need to be in the range of
192.168.1.2 thru 192.168.1.99 or
192.168.1.150 thru 192.168.1.254
assuming you are still using the default DHCP server range.
Also, in the computer, when you set up a static LAN IP address, you would need to set the "Subnet mask" to 255.255.255.0 and the "Default Gateway" to 192.168.1.1 and "DNS server" to 192.168.1.1
It is also important that no two devices on your network be set to the same static LAN IP address.
Check all of your static LAN IP addresses. If you have violated any of the above rules for static LAN IP addresses, it could be the cause for your problem, and you should fix it before attempting any other router repairs or changes.
********* Wireless Security **********
Brfore proceeding with wireless security, you must get your IP address conflict problem solved. Please do the above first.
To set up wireless security, you must use a computer that is wired to the router.
Where to find the router settings: The router's login password is usually on one of the "Administration" pages. The other settings are all found in the "Wireless" or the "Security" section of the router's setup pages, located at 192.168.1.1
First, give your router a unique SSID. Don't use "linksys".
Make sure "SSID Broadcast" is set to "enabled".
Next, leave the router at its default wireless settings (except for the unique SSID), and then use your pc to connect wirelessly to the router. Test your wireless Internet connection and make sure it is working correctly. You must have a properly working wireless connection before setting up wireless security.
To implement wireless security, you need to do one step at a time, then verify that you can still connect your wireless computer to the router.
Next, encrypt your wireless system using the highest level of encryption that all of your wireless devices will support. Common encryption methods are:
WEP - poor (see note below)
WPA (sometimes called PSK, or WPA with TKIP) - good
WPA2 (sometimes called PSK2, or WPA with AES) - best
WPA and WPA2 sometimes come in versions of "personal" and "enterprise". Most home users should use "personal". Also, if you have a choice between AES and TKIP, and your wireless equipment is capable of both, choose AES. With any encryption method, you will need to supply a key (sometimes called a "password" ).
The wireless devices (computers, printers, etc.) that you have will need to be set up with the SSID, encryption method, and key that matches what you entered in the router.
Retest your system and verify that your wireless Internet connection is still working correctly.
And don't forget to give your router a new login password.
Picking Passwords (keys): You should never use a dictionary word as a password. If you use a dictionary word as a password, even WPA2 can be cracked in a few minutes. When you pick your login password and encryption key (or password or passphrase) you should use a random combination of capital letters, small letters, and numbers, but no spaces. A login password, should be 12 characters or more. WPA and WPA2 passwords should be at least 24 characters. Note: Your key, password, or passphrase must not have any spaces in it.
Most home users should have their routers set so that "remote management" of the router is disabled. If you must have this option enabled, then your login password must be increased to a minumum of 24 random characters.
One additional issue is that Windows XP requires a patch to run WPA2. The patch is located in SP3, so you will need SP3 to run WPA2 in Win XP. Vista already supports WPA2.
Note:
WEP is no longer recommended. The FBI has demonstrated that WEP can be cracked in just a few minutes using software tools that are readily available over the Internet. Even a long random character password will not protect you with WEP. You should be using WPA or preferably WPA2 encryption.

I/O addresses conflict with KT4AV

Hi,
My system: KT4AV, Athlon 2800+, 512 MB, Radeon 9200, Windows 2000 pro.
When I install normally Windows 2000 pro the computer type in device manager is Uniprocessor ACPI. BUT I also get a Hardware I/O addresses conflict on motherboard resources: conflicts with DMA, Keyboard, System timer, ...(Address range 0800-087F).
I would like to keep ACPI HAL but I would ALSO like to get rid of these conflicts!
Any help appreciated.
Regs

Don't know too much about Windows 2000, I'm afraid. Checked Windows, but I guess you have been there. But maybe you find what you are looking for. Hope so!
To sort of amuse you a little ironically I withsend a quote:
http://search.microsoft.com/search/results.aspx?View=en-us&p=1&s=0&c=4&st=b&qu=i%2fo+conflict+2000&na=30
"User Action:
Contact your system administrator. Check the configuration of the adapter card by selecting Network in Control Panel. Make sure the adapter card is configured according to the manufacturer's specifications and that the card's configuration does not conflict with the configurations of other hardware. "

IP address conflict with alias

Hello,
I have two CSM 4.1(5) in CatOS 6509 configured in router mode.
I have configured one client VLAN and 2 servers VLANs (with aliases IP adresses), and an ft dedicated gigabit link.
The configuration is the same for both server VLANS :
vlan z server
ip address x.x.x.x x.x.x.x
alias y.y.y.y y.y.y.y
The logs show an IP address conflict for one server VLAN with the alias IP address configured for this VLAN, whereas there is no problem for the other server VLAN.
This problem causes the CSM going to active-active configuration for a very short time (1sec) and then going back to active-backup situation during about 30 sec.
Does anybody have an idea about the problem ? I could not find any documentation to know if more than one server VLAN with an alias could cause a problem in router mode or an issue related to that.
Thanks,
Herve.

Herve,
should not be a problem.
You can have as many server vlan with alias as you want.
The CSM does box redundancy [per box not per vlan].
So if the CSM is active, it will be active for all vlans not just a one or a few of them.
Sniff the ft vlan and make sure there is heartbeat sent from both site.
Sniff traffic coming in and out of both csm to make sure they both receive and transmit.
Capture 'sho mod csm x ft detail' several times and check the transmit/receive counters.
Gilles.

IP Address Conflicts - iMac and Airport Express, Snow Leopard and Mountain Lion

In our home we have an iMac, two Mac notebooks, an iPad, an Apple TV and a Sony Playstation that all use wi-fi. I have a recurring problem. When several devices are connected to the Internet through Airport Extreme (wi-fi) downloads really slow down. Since the Airport Extreme is connected directly to a Motorola cable modem that also has wi-fi, I often shift my iMac wi-fi connection to the Motorola cable modem to speed up the Internet. Lately I have been getting an IP address conflict message in a pop-up box when I shift to the cable modem wi-fi. The system preference shows the IP address automatically assigned via DCHP. It also offers the option of DHCP plus manual.
I am now using Snow Leopard and intend to upgrade to Mountain Lion.
How can I resolve the conflict? Or, should I consider some other wifi network configuration? Is the upgrade to Mountain Lion likely to resolve the problem or make it worse? Can I use the DHCP plus manual to manually assign an IP address to the iMac to resolve the IP address conflict, and, if so, what it the procedure?

Is the DHCP assignment being done by your cable modem or your AirPort Extreme?
What is the exact text of the conlict message, and where does it pop up?
If your cable modem and your AirPort Extreme are both running DHCP servers for the same subnet (which they really should not be allowed to do), they must be set to assign addresses from disjoint pools.

IP Address Conflict

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