# DHCP Issue...



## Scoob_The_Kid (Jun 30, 2011)

OK, I have been working on this for about a day now. When trying to renew IP, I get this error "An error occurred while renewing the interface Local Area Connection: The DHCP client has obtained an IP address that is already in use on the network. The local interface will be disabled until the DHCP client can obtain a new address." 

Plastered all over the internet is this; 
Resolution: 1. Release and then renew it. 2. Clean the internal DNS and WINS records. Refer to case 083104LR (what is case 083104LR???)

I have released and renewed it, it didn't work. I was guessing the DNS is the /flushdns /registerdns I have done that as well. But I don't quite know how to clean the WINS records

I am on a network at a small business. We have a very...archaic hook up, and it's tough to explain. So if you can bear with me and picture a computer hooked into a 5 port router (with only 2 computers in it, if that makes a difference) that is hooked into an extension that runs under floors along walls, and up stairs to a netgear 8 port (6 ports used, and this allows us to share the scans from the printer.), which goes into a netgear 5 port, and then into the quest router, which delivers the internet. 

I had this problem with another computer months ago, and I directly connected it to the router, which solved the problem. However this computer needs to make it into the 8 port set up, because then we can recieve scans from the printer, and it will be tied into the "network". 

I took the computer tower out of the cramped space it was in, and I cleaned it started checking to see if it was the ports, wires, or the router that was the problem. When I got everything back, it worked again. So I put it back into it's area, and it stopped working again.....please help


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## Old Rich (May 31, 2007)

Is the ethernet cable the same when you connected out of the cramped space?


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## Wand3r3r (Sep 17, 2010)

so in reverse you have 
qwest router<>bunch of switches<>router correct?

nothing is connected to the last routers wan port or is it cabled to the wan port?

if you connect to one of the switches does internet work?
its only when you connect to the last router that doesn't work?


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## Scoob_The_Kid (Jun 30, 2011)

yes, I even switched it with another working computer to see. So i have a new chord, that was working for another computer.


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## Scoob_The_Kid (Jun 30, 2011)

Wand3r3r said:


> so in reverse you have
> qwest router<>bunch of switches<>router correct?
> 
> nothing is connected to the last routers wan port or is it cabled to the wan port?
> ...


I'm not sure what the wan port is, I don't see that on the routers. What works to connect it to the internet is bypassing all the different routers, and connecting it to the quest internet router. BUT I want it to work while being set into at least the 8 port router. It does not work when I bypass the first router and go to the 8 port. 


I just went and re-did the renew release, flush and register dns. reset the first router and the computer. No luck.

EDIT: If by switches you mean, different routers, then yes. correct. so quest>5ports>8ports>5ports>computer


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## Wand3r3r (Sep 17, 2010)

from your first description the 8 port is a switch not a router. need to be clear on the difference between a switch and a router. switches have no wan ports. on the qwest router the line going to the modem is connected to the wan port of the router.

Connect to the qwest router and post the results of a ipconfig /all
then connect to a switch [not the router at the end of the chain] and do another ipconfig /all.
then connect to the last router and do another ipconfig /all

post all three ipconfigs /all noting which is which connection for review. Thx


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## Scoob_The_Kid (Jun 30, 2011)

Ok now that I know what a switch vs. router is, they are all switches from the computer back to the qwest router. I got this 

first switch
C:\Documents and Settings\Owner>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : SHOWROOM
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VIA Rhine II Fast Ethernet Adapter
Physical Address. . . . . . . . . : 00-14-85-51-8E-63
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 0.0.0.0
Subnet Mask . . . . . . . . . . . : 0.0.0.0
Default Gateway . . . . . . . . . :
DHCP Server . . . . . . . . . . . : 255.255.255.255

connected to the router

C:\Documents and Settings\Owner>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : SHOWROOM
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VIA Rhine II Fast Ethernet Adapter
Physical Address. . . . . . . . . : 00-14-85-51-8E-63
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.0.4
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 192.168.0.1
205.171.3.25
Lease Obtained. . . . . . . . . . : Thursday, June 30, 2011 4:10:52 PM
Lease Expires . . . . . . . . . . : Friday, July 01, 2011 4:10:52 PM

connecting it to the 8 port switch

C:\Documents and Settings\Owner>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : SHOWROOM
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VIA Rhine II Fast Ethernet Adapter
Physical Address. . . . . . . . . : 00-14-85-51-8E-63
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.0.4
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 192.168.0.1
205.171.3.25
Lease Obtained. . . . . . . . . . : Thursday, June 30, 2011 4:10:52 PM
Lease Expires . . . . . . . . . . : Friday, July 01, 2011 4:10:52 PM
C:\Documents and Settings\Owner>

I was so excited that the 8 port switch worked, I was going to say thanks and end it here. But another computer quit working when I did that. One that is connected in the 5 port switch, between the 8 and the router. So I connected that computer straight to the qwest router to give her internet, she has to send the order for our store. I went downstairs and the computer was down, ipconfig /all showed this.

C:\Documents and Settings\Owner>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : SHOWROOM
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VIA Rhine II Fast Ethernet Adapter
Physical Address. . . . . . . . . : 00-14-85-51-8E-63
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 0.0.0.0
Subnet Mask . . . . . . . . . . . : 0.0.0.0
Default Gateway . . . . . . . . . :
DHCP Server . . . . . . . . . . . : 255.255.255.255


Just not my day.  Not only that, both usb ports are now useless, I found the plastic end of the usb port still in my usb drive. (not my fault it was broken previously.)


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## Wand3r3r (Sep 17, 2010)

you need to logon to the qwest router and review the dhcp scope settings.
make sure they are set to 192.168.0.2 to 192.168.0.254 which is the max.

Then try your connections again.

either the routes dhcp server 
doesn't have a big enough dhcp scope
isn't working right
lan ports are failing
or
cabling between switches is failing
switches are failing


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## Scoob_The_Kid (Jun 30, 2011)

OK, I really don't want to waste your time, but I need the help. I'm not sure how to log on to the router to see that. How would I go about doing that?


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## Wand3r3r (Sep 17, 2010)

Not wasting my time. That's what I do here 

Does anyone know the account name and password for the router?
Documented somewhere?

you connect a pc to the router
you type 192.168.0.1 into a browser
you are presented with a logon screen asking for user and password.
usually admin and a password

If no one knows you can try calling qwest tech support and see if they can access the router if they provided it.

otherwise this can get messy. 

If you can't get into the router we would bypass this and make sure the first switch and its cable to the router isnt' the fault. You would test by plugging your pc into the cable going to the router that the switch uses to connect to the router. if you get ip and internet your next step would be to do a ping yahoo.com -t then giggle the cable a bit to see if you get intermittent fails. Control C to discontinue the ping. If all is good hook up the switch to the line and do the same being connected to the switch to see if you get ip and internet. if no go replace the switch. do this all the way up the line to the last switch.

Once the cables and switchs are confirmed as working we would go back to work on the router.


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## Scoob_The_Kid (Jun 30, 2011)

I know the username and password, thank goodness for a boss that holds everything! Ok, so it's set for 192.168.0.2 to 192.168.0.254. I will start with the trying out the chord's and such, however, I won't be back until tuesday to finish this. They will have to deal with it. Thanks for your help!! Please look for a post tuesday, I will need the help! thanks!! Enjoy the 4th! Safe travels, and be safe with your fireworks!


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## Wand3r3r (Sep 17, 2010)

You also and thanks


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## Proxyman (May 30, 2011)

In case this is useful:

I see this error frequently on one client's network. They have a switch and not a router, so maybe it's something that is common to having a switch.

What I do is manually configure an IP Address to the machine that is throwing the error. Pick one that is not being used. Once it's running (I leave it that way for 10 minutes to a day), then change the manual configuration back to DHCP. The IP Address you assigned manually is retained, even though it's set back to DHCP.

I don't know why it works, but it does. Maybe it will work for you.


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## Wand3r3r (Sep 17, 2010)

"They have a switch and not a router"

very surprising this would ever work if they were getting ips provided ip.


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## Proxyman (May 30, 2011)

Wand3r3r said:


> "They have a switch and not a router"
> 
> very surprising this would ever work if they were getting ips provided ip.


I meant internal IP's. That's the OP's problem, right? as in 192.168.0.xxx, etc... The external IP is static to allow LogMeIn, etc...


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## Wand3r3r (Sep 17, 2010)

problem is in cabling or failing switches not passing data thru


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## Proxyman (May 30, 2011)

Scoob_The_Kid said:


> OK, I have been working on this for about a day now. When trying to renew IP, I get this error "An error occurred while renewing the interface Local Area Connection: The DHCP client has obtained an IP address *that is already in use on the network*. The local interface will be disabled until the DHCP client can obtain a new address."





Wand3r3r said:


> problem is in cabling or failing switches not passing data thru


How does a problem with failing switches or cabling cause DHCP to assign a duplicate IP Address within the network? The OP does not report any other problem on the network. In my case, all machines (computers, laptops and printers) work perfectly. The only problem is a duplicate IP Address, and manually changing it to "something else" fixes it (in my case).

How does a hardware problem cause these symptoms?


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## ToiletBlaster (Jul 3, 2011)

It sounds like to me that you have two routers with DHCP switched on, try using only the one connected to the Internet supplying DHCP and the other should be passing through or DHCP switched off, give this router a static ip on the same network as the first say 192.168.0.2 and change the DHCP scope on the Internet connected router to 192.168.0.3 - 192.168.0.254. This should sort your problem


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## Wand3r3r (Sep 17, 2010)

"they are all switches from the computer back to the qwest router"

"How does a problem with failing switches or cabling cause DHCP to assign a duplicate IP Address within the network? "

If there is a problem with cabling/switching/communicating to the dhcp server a computer with a lease not expired can conflict with a new assignment of the same ip by the dhcp server since according to the dhcp server the first assigned ip is not longer active.

This is what is supposed to happen but with intermittent failure of hardware it doesn't complete.

After the DHCP client receives a lease from the DHCP server, the client sends an Address Resolution Protocol (ARP) request to the address that it has been assigned. If a reply to the ARP request is received, the client has detected a conflict and sends a DHCPDecline message to the DHCP server. The DHCP server attaches a BAD_ADDRESS value to the IP address in the scope for the length of the lease. *The client then begins the lease process again, and is offered the next available address in the scope.*

from here
How DHCP Technology Works: Dynamic Host Configuration Protocol (DHCP)

though I don't think soho router dhcp servers do the bad address entry.

I would also add that if you review you will see when connected to router it works yet if there was another router doing dhcp it would occure for all devices no matter what switch/router they were connected to.


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## Scoob_The_Kid (Jun 30, 2011)

Alrighty....So I don't want to rule any of the solutions out before I try them. I will check the wires, and switches. However, while I do that could you tell me how I could manually set my IP address? 

I think that could work, and the reason I say that, is because no matter where I'm plugged into the switch it doesn't work. But any other computer would work in that same port, with the same wire.


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## Wand3r3r (Sep 17, 2010)

Scoob if you set a ip address on a pc you are asking for ip conflicts if everyone is set to obtain ip automatically.

If you are going to set a static ip you have to do the following:

Go into the router and change the ip scope from 2-254 to 2-253

Go into your tcp/ip properties and change from obtain ip automatically and assign a ip like so
192.168.0.254 ip
255.255.255.0 subnet
192.168.0.1 gateway
192.168.0.1 dns

I would suggest instead you go visit every device on the network including printers and write down [document] if set to dhcp or if they have a static ip.

for example what ip does the network printer have?

according to your first post everything have been working until you had that one pc not work on the 8 port but did work on the router which is what pointed me to failing cabling/switch(s)


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## Scoob_The_Kid (Jun 30, 2011)

ok. It's a tricky situation on when I get to work with the computers. I also have to work the floor of the store, and I don't get to devote my whole time to working on the computers. However I have had time to figure out how to manually set up my ip, and that did not work. So when I get some time today...if I get some time today then I will test out the wires and switches...


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## Scoob_The_Kid (Jun 30, 2011)

sorry wand3r3r I didn't see your post tell after I posted, I would rather not go through and document all of our devices, as I don't know where all of them are, nor how to find them all. I just know if I don't get this done soon I will have to be writing alot of tags...


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## Scoob_The_Kid (Jun 30, 2011)

Well from what I have seen, we have one computer that is set up to obtain the ip address that is specified, all others obtain automatically, I just don't know what the printer is on. =\ How would I find that?


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## Scoob_The_Kid (Jun 30, 2011)

Sorry for the Quad posting, If I could find a way to edit those I would. However, exciting news for me! It works. I changed the scope to 168.0.253, and I changed the address to 2.0.25 and I coppied what the one computer's settings were. It works like a charm now, just in time for me to find out what is happening in the Casey Anthony trial oh happy day....Thank you for all your help Wand3r3r and Proxyman without you I wouldn't have gotten this done. I now love this forum!  It has everything. If you ever need help with graphics, or signatures please hit me up1!


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## Proxyman (May 30, 2011)

Well I'm glad you've got it working and all, congratulations etc... etc... but 

HUH?

What did you do? "scope" ? IP Address "2.0.25"?

Or are you still editing your post, lol?


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## Wand3r3r (Sep 17, 2010)

If you don't document and also fix the routers dhcp scope its just a matter of time before you have the same issue but more so since you have done another static ip assignment.

In other words you didn't solve the issue but only delayed it.


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## Scoob_The_Kid (Jun 30, 2011)

Sorry one last thing I thought of that could help someone in a similar situation. I hooked the computer up into the closest switch to the router, and changed the ip as well. Just so you know.


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## Scoob_The_Kid (Jun 30, 2011)

Proxyman said:


> Well I'm glad you've got it working and all, congratulations etc... etc... but
> 
> HUH?
> 
> ...


Ok by scope, I mean the range of ip addresses in use. I changed the scope or range from 192.168.0.2 - 192.168.0.254 to 192.168.0.253. 
The IP address I changed on the computer with the problems was changed to 192.168.0.25. >.< I meant 8 not 2 as my starting number, I was trying to save time.



> If you don't document and also fix the routers dhcp scope its just a matter of time before you have the same issue but more so since you have done another static ip assignment.
> 
> In other words you didn't solve the issue but only delayed it.


What would you suggest the easiest way to document it? Maybe copy and paste ipconfig /all to a notepad or word file and save it somewhere? Maybe e-mail it to myself from that computer? Also should I set them all up with a static IP?


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## Wand3r3r (Sep 17, 2010)

easiest way is to go into the router and look at 'connected devices'.
you will see a list of machine names and ip addresses.

make sure first, that every network device is on

if you don't have time to visit every machine/devices to document its setting you certainly don't have time to do static ip assignments.

concerning the printer it should have a menu interface. you go into the system setup options to see the tcp/ip setup


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## Scoob_The_Kid (Jun 30, 2011)

IT's not so much that I don't have the time. It would just take a few days to do it. And if it will save me time in the long run, and you think it would be wise, then maybe I should.


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## Proxyman (May 30, 2011)

I want to go back to the point where wanderer said it was a cabling issue.


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## Wand3r3r (Sep 17, 2010)

Scoob usually you only set devices like servers, managed switches, routers to static ip. It is much easier to use dhcp to control everything else

Going to do all static assignments is really off track for your issue(s).

If you have a pc that gets ip when connected to the router, it should get ip on any switch off that router. This points to cabling/switch failure.

Also since you don't have the network documented concerning those devices with static ip, no one knows if the dhcp scope in the router contains the same ips available to be passed out. This can cause a ip conflict.

Do you see what you need to address from this?


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## Scoob_The_Kid (Jun 30, 2011)

I think so, I need to find out what IP's my switches have to hand out. Or I need to figure out the allowed IP's my router is sending?

One thing I notice on this computer, and none others. If the Internet Explorer isn't brought up for a while, it asks me if I want to work off line when I bring it up. I just click try again and it kicks online, but should I be worried?

EDIT* How would I go about setting up my switches with static IP?


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## Wand3r3r (Sep 17, 2010)

Scoob switches don't hand out ips.
You only assign static ips to managed switches. So far in all your posts I see no indication you have managed switches.

You can't assign ips to unmanaged switches since there would be no point. You manage a switch via its ip address. no management - no need for a ip

Have you gone into the router and documented all of the attached devices?


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## Scoob_The_Kid (Jun 30, 2011)

I may have found our problem boss! Ok so the Qwest Modem, has 2 user's at 192.168.0.2 and .3 (If I could provide a screen shot I would.) What I thought to be a switch was a router, the 5 port between the router and the 8port switch. SSOOO I was trying to log into my modem interface, screen shot it on my personal computer, but I couldn't log in...after the past 45 minutes on tech help through quest, I figured out that I am using a router, and I will have all the IP's Documented tomorrow...I really hope that this second router was my problem and I can fix it now...


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## Wand3r3r (Sep 17, 2010)

As you can see. understanding what equipment you are using is important.

If you have a second router one of the ways to tell is lookup the make and model.


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## Scoob_The_Kid (Jun 30, 2011)

I found that out by looking at the directions on the back. I was guessing the "WAN" port would be where the internet goes. It has one of those, and I figured it was a router....remember my ipconfig showing me the computer had 168.0.3? Well the main router has another computer using that same address...

Edit* With the lack of knowledge I had on our equipment, you see why I came here. 

EDIT** On a closer look at this router, it only is giving out 3 IP Addresses... It should be giving out 4 if not all 5...how do I figure out the device name to go with the device? Unplug it and see what disappears?


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## Scoob_The_Kid (Jun 30, 2011)

nvm, I did a scan and found 6 devices attached to it. I figured out my printer's IP and see the rest of the computers, but still how can I figure out which computer is which?


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## Proxyman (May 30, 2011)

Scoob_The_Kid said:


> nvm, I did a scan and found 6 devices attached to it. I figured out my printer's IP and see the rest of the computers, but still how can I figure out which computer is which?


Unplug one computer and figure out which one just lost internet.


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## rwilcher (Jul 3, 2008)

Perhaps theres some Macaddress/IP address confusion going on ?
Somebody sees the mac address and hands out the same IP again ?
just a thought.


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## Scoob_The_Kid (Jun 30, 2011)

http://www.techsupportforum.com/forums/f136/cable-says-its-unplugged-589812.html#post3365915

Wand3r3r I need your help  I think you were right I was wrong fits well in this situation....


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