| [Help Me] DWL-G710 "IP address conflict" Question I've got a very small network setup in my townhouse. DSL modem feeds into DI-524 router, which is the DHCP server. Desktop PC hooked into DI-524 and a single wireless laptop with a DWL-G630 card. To increase wireless range onto my ground floor (DI-524 is on third floor in the office), I added the DWL-G710 range extender. DI-524 and DWL-G710 have firmware upgrades.
Setting up the DWL-G710 was no problem. The problem I am having is that when I added the DWL-G710 and connect to it with my laptop, I get pretty regular pop-ups that say "Windows - System Error // There is an IP address conflict with another system on the network" Only trouble is, I know this isn't the case (each device has unique IP address) and it only happens when connected to the DWL-G710. I changed the static IP address of the G710, but it is outside of the range where my DHCP server can assign, so I'm sure that isn't the problem. Laptop operating system is XP home.
The warnings can always be made to appear when I try to ping my desktop (IP address ends in .100) from my laptop (address ends in .101).
I've tried all of the normal trouble-shooting steps, such as enabling/disabling encryption, power cycling everything, enabling/disabling DHCP always with the same result. The conflict warnings are still there.
Has anyone ever seen anything like this? Three calls to D-link tech support have come up empty and searching through discussion groups has as well. Any thoughts or suggestions are appreciated. Thanks. |
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 funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5 | First, go to your desktop machines and look at Network Connections. See if there are any icons for Incoming Connections. If so, delete the incoming connection, unplug power/reboot everything, and try again.
That could be on your laptop as well.
If that's not the issue, then try this:
The next time you get that message, go to Event Viewer (Start, Run, EVENTVWR.MSC) and check the System and Application logs. Look for an entry that says this:
"The system detected an address conflict for IP address 192.168.1.100 with the system having network hardware address 00:0C:41:9B:88:89"
That hardware address will be the MAC address you need to find.
Running IPCONFIG /ALL will display all the active MAC addresses in your computer.
--
Robb Topolski -= funchords.com =- Hillsboro, Oregon USA
~ Keeper of the D-Link FAQ ~ Did you Search? ~ More features, Free! Join BBR! ~ |
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| reply to mmacedon
Thanks for your reply. I checked both machines and there are no other internet connections on either.
I checked the laptop event log too, and here is what is indicated.
"The system detected an address conflict for IP address 192.240.24.101 with the system having network hardware address 00:13:46:BA:E2:00. Network operations on this system may be disrupted as a result."
That MAC address is the DWL-G710. The static IP address of the DWL-G710 on my system is 192.240.24.99 and my DHCP server is allowed to assign addressed from 192.240.24.100 to 192.240.24.199.
That's where I'm stuck right now. Thoughts or suggestions? Thanks. |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5
1 edit | A couple of thoughts:
•With the laptop turned off, Go to your desktop machine and type ping "192.168.24.101" followed by "arp -a" at a command prompt. This command will tell you about the IP addresses it has recently heard from, and about the MAC addresses that last transmitted using the IP.
If it heard it through the bridge (or if it is the bridge), it's going to have the bridge's address. But since the laptop is getting the bridge's address in the error message, we want to see what the desktop has heard.
•Check your DHCP server to see if there are any reservations, unexpired, unrevoked entries for that MAC address. If your DHCP server has logging, look for clues there.
--
Robb Topolski -= funchords.com =- Hillsboro, Oregon USA
~ Keeper of the D-Link FAQ ~ Did you Search? ~ More features, Free! Join BBR! ~ |
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| reply to mmacedon
I checked the arp -a on both machines. When the laptop is turned off, I can't ping its address at all from the desktop. When it is on, and I ping it from the desktop, there are two situations.
If the laptop's wireless connection is associated with the router (DI-524), the results of the arp -a show that its IP address origninates from physical address of the wireless card in my laptop.
If the laptop's wireless connection is associated with the repeater (DWL-G710), the results of the arp -a show that its IP address originates from the physical address of the repeater.
The desktop sees the laptop's address as originating from the repeater's physical address when the laptop is connected to it. So, it makes sense then that the laptop sees a conflict when the DWL-G710 "repeats" its signal (with same IP adress as the laptop, but with a different physical address). Is that the way its supposed to work? If so, I don't see how the conflict can be avoided. |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5 | said by mmacedon :
So, it makes sense then that the laptop sees a conflict when the DWL-G710 "repeats" its signal (with same IP adress as the laptop, but with a different physical address). Is that the way its supposed to work? If so, I don't see how the conflict can be avoided.
I -might- be able to join you in this theory ... but there are several reasons why not.
I spent a good hour thinking on this one.
I think the problem is because your network stack doesn't seem to be changing to "Media Disconnected" state when you disassociate from the DI-524, DWL-G710, or unplug a wired connection. Going to Media Disconnected state removes the TCP/IP assignment from the stack.
One of the reasons can be because your wireless card is part of a Bridged Connection in Windows. Go to Network Connections on the laptop and look for the mention of a MAC Bridge Miniport. If it appears there, delete it (it is easily recreated, but is usually unnecessary). This operation takes a minute or so. Then reboot the computer and test again.
If you did not have a bridge configured in Network Connections, or if the above didn't work, here's what I'd like to see ...
Your laptop's "arp -a" output from before the ping and warning, and then the "arp -a" output from after (2 outputs, total).
"IPCONFIG /ALL" from the laptop from before the ping, and then from after (2 total).
--
Robb Topolski -= funchords.com =- Hillsboro, Oregon USA
~ Keeper of the D-Link FAQ ~ Did you Search? ~ More features, Free! Join BBR! ~ |
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| reply to mmacedon
Thanks again for all of your help. There were no bridged connections in the laptop.
I hate to admit it, but I have abandoned the repeater idea. Based on what I've been reading in many of these boards, increasing the range of my network may be more effectively done by getting a directional, higher gain antenna for my original router.
I got a hawking tech 15dbi corner antenna for my router and that fixed the weak coverage problem in the basement. Of course, this also didn't come with the associated IP conflict and reduced throughput problems of the repeater. Anyway, all is well now (although I hated giving up on the networking problem I couldn't understand). Thanks again for all of your help.
-Mike |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5 | OH NO! I'm disappointed!
Actually I'm glad for you. I just wish I could figure out what was causing all of that ruckus!
Congrats! Yes, the directional antenna is a better choice for so many reasons! |
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| reply to mmacedon
Re: [Help Me] DWL-G710 "IP address conflict" Quest Just for theoretical reasons:
How about one of the devices occupying more then one IP without explicitly mentioning it? That is, separating further the DHCP-scope from the device's known IP might help?
Have fun with high-gain-antennae!
Purgatorio |
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| reply to mmacedon
I've had exactly the same problem, but with a DI-624 AP and
a DWL-G800AP in repeater mode. Additional information:
o if my wireless devices (i.e. laptop) is close to the repeater, and clearly using it, no problems occur.
o if my wireless devices are between the repeater and the DI-624 -- problems.
I *think* I've finally worked around the problem by turning OFF the DI-624 DHCP server, altogether, and assigning static IP addresses to all of my machines. DLink support was marginally helpful, but mostly just recommended upgrading firmware.
This is not pretty, and a pain when a laptop is mobile, but it seems to work (at least today).
George |
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| reply to funchords
Re: [Help Me] DWL-G710 "IP address conflict" Question Hello,
I am having the same problem as the person you were trying to help. I have followed the thread and have done everything up until the mini-port removal, to no avail. When I us "ipconfig /all" I see a mini-port, however, when I go to "Network Connections," as you recommended, I do not see a "Mini-port" or "Bridge". I bet that the last person you were trying to help did have a mini-port (and would have seen it when using "ipconfig"), but, like me, did not see it in "Network Connections". I am convinced that the "Mini-port" is the problem, but cannot seem to find it to remove it. Please help! Thanks. |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5 | Re: [Help Me] DWL-G710 "IP address conflict" Quest There are two mini-ports that are very common -- one is the bridge that we've been talking about, the other is the Packet Scheduler Miniport (PSCHED).
PSCHED is installed by default, but is usually not used unless something on your machine is enabled for prioritized packets (e.g. video/voice gets higher priority than P2P downloads).
So if the miniport you are seeing is PSCHED, it is not the problem.
Do an 'IPCONFIG /ALL' and copy it into here and I'll see what I can see. Meanwhile, I have a different theory.
If you are connecting through a repeater, then immediately configure to connect directly to the AP, and/or go back and forth without explicitly disconnecting first -- you will have TCP/IP conflicts because the ARP cache is not cleared.
This is a bug I discovered in Windows, but I'm certain that it's actually in the specification.
The ARP cache is a table mapping IP addresses to MAC addresses. The ARP cache is cleared when TCP/IP is bound or removed from a network device. This happens when you disconnect, but it doesn't happen when you move from connection to connection!
So, when you move from repeater to AP, the ARP table can't take the new entry because it already has one for that IP address! Viola -- you get the conflict message.
I've reproduced this in a couple of different ways and I think it might have something to do with the O.P.'s original problem, too.
To work around it, make sure you disconnect from the previous connection path, then reconnect to the same device. This clears the ARP cache.
You can also do the command "ARP -d *" as another workaround.
--
Robb Topolski -= funchords.com =- Hillsboro, Oregon USA
~ Keeper of the D-Link FAQ ~ Did you Search? ~ More features, Free! Join BBR! ~ |
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| reply to gmfeinberg
For what it's worth, turning off the DHCP server on the
router didn't help anything. I'm still having the
problem. |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5
1 edit | said by gmfeinberg :
For what it's worth, turning off the DHCP server on the
router didn't help anything. I'm still having the
problem.
Try these suggestions:
To work around it, make sure you disconnect from the previous connection path, then reconnect to the same device. This clears the ARP cache.
You can also do the command ...
ARP -d *
... as another workaround. --
Robb Topolski -= funchords.com =- Hillsboro, Oregon USA
~ Keeper of the D-Link FAQ ~ Did you Search? ~ More features, Free! Join BBR! ~ |
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| I've found a solution.
The conflict is occuring as a result of a Windows machine
trying to detect possible IP address conflicts using
what's called a "Gratuitous ARP." This is usually a
fine thing to do, but...
There are 2 problems here:
1. The fact that the repeater is answering the
Windows "Gratuitous ARP" using its own MAC address.
2. The "Gratuitous ARP" itself, which is sent by the TCP/IP
stack in Windows to detect conflicting IP addresses.
I cannot control or fix (1), but (2) can be "fixed" by
turning off the ARP. If you search the net for "disable
gratuitous arp" you'll find a bunch of Microsoft knowledge
base references to a registry setting in the tcpip parameters called "ArpRetryCount"
The specific registry key is:
HKEY_LOCAL_MACHINE->SYSTEM->CurrentControlSet->Services->Tcpip->Parameters->ArpRetryCount
The articles also imply that this setting does not
apply to Windows XP, and you will not find that key
in your registry, either. However, it does apply.
You just need to add it as a new DWORD key, with
the value set to 0.
Note that this is a semi-dangerous thing to do if you
spend a lot of time on open wireless networks, because
IP address conflicts can happen, and are bad. But for
a controlled, home network, it's safe.
George |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5 | Wow!!!!!!!!
Thanks!!
I'm so glad you let me know ... and congrats on finding it! |
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| If anyone is interested I am having this same problem... I got fed up with firmware upgrades and downgrades and configuration and I finally came to the conclusion that it was an ARP problem like all of you did. I was so sick of it I came up with the following workaround:
1. Create a batch file that fixes the ARP problem with static ARP
fixarp.bat
##########
@echo off
arp -d *
arp -s 10.10.10.1 00-0f-3d-06-81-a9 REM Replace with your ROUTER MAC ADDRESS
2. (Optional) Create a batch file that checks arp status
checkarp.bat
############
arp -a
pause
3. Save these files on the desktop for easy access. |
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funchordsHelloPremium,MVM
join:2001-03-11
Yarmouth Port, MA
kudos:5 | arp -d * will do it. The router will be found via an arp "WHO HAS" request broadcast. |
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