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2 MacBooks, 1 IP, Getting Online Conflict...

N

newomij

macrumors newbie
Original poster
Feb 22, 2013
11
0
Seattle
I'm new to Mac so everything is new and frustratingly hard to find. If not for MacRumors and search engines...

My wife and I have matching MacBooks with Mountain Lion. Frequently, one of us will be online wirelessly when the other will try to get online wirelessly or direct connect and both of us will get a message that "another device with the same IP address is trying to get online", meaning the second of the two MacBooks. At that point, the one trying to get online is denied access and the one that's already online is dropped and requires a power disconnect of the router before either of us can get back online.

Is this a common problem with an easy solution?:confused:

PS In addition to the two MacBooks, we have a VOiP phone system and the Sprint Rave connected to the router as well. When it calls for the router to be reset, I have to reset the Sprint Rave, also. The VOiP phone system doesn't seem to mind all the power downs and ups.
 
i will give you a way and i hope help you . go to System Preferences , then go to Networks , in the left side you will see all devices which connect by your machine , the most important thing you do go to function which you connect to the internet by it . after you press it , then press advanced in right bottom of network's window . then you will see new window go to TCP/IP and press on Renew DHCP Lease .
( Use these steps in both devices )

I hope this replay help you to solve your problem
 
"go to System Preferences , then go to Networks , in the left side you will see all devices which connect by your machine , the most important thing you do go to function which you connect to the internet by it . after you press it , then press advanced in right bottom of network's window . then you will see new window go to TCP/IP and press on Renew DHCP Lease .
( Use these steps in both devices )"

This did not work. Followed the instructions above and pressed on Renew DHCP Lease on both MacBooks at the same time. When we did that, it asked for something in the box just below that. Were we supposed to have a number to go into that box?
 
still looking for a solution...

I tried the suggestions from the last post from 'SomeZeros' but with no resolution.

Of course, I am still looking for the solution 'cause it's still happening and every time one of us try to get online while the other is already online, we get the same message that another device with the same IP is trying to access the router. The one trying to get on is denied while the one with the connection is terminated.

Any one out there think of solution?:confused:
 
what Kind of router are you using? Have you checked with the manufacturer of the router to see if there is a firmware update and checked their support section.

Two systems with different MAC addresses on the LAN/wlan cards should not be able to get the same IP assigned.

Also have you checked your router to ensure that it has enough DHCP addresses available in the pool of addresses? I.E. 192.168.1.100 - 192.168.1.150? or more?
 
AshMan said:
Two systems with different MAC addresses on the LAN/wlan cards should not be able to get the same IP assigned.
Click to expand...

I agree. This should not happen. Thenagain, some ISP's have (at least: used to have) some stupid rules limiting the number of devices which could use the router. I know that I once encountered this when trying to help out a neighbor, and the way this was managed was that the ISP's router had a DHCP IP range limited to one single IP.

OP, if you can, dig up the friendly manual which came with your router and try to get into the management software of that router (usually this happens by typing an IP like 192.168.0.1 into the nearest browser) and check around there...

RGDS,
 
seveej said:
I agree. This should not happen. Thenagain, some ISP's have (at least: used to have) some stupid rules limiting the number of devices which could use the router. I know that I once encountered this when trying to help out a neighbor, and the way this was managed was that the ISP's router had a DHCP IP range limited to one single IP.
Click to expand...

This is what I was thinking. perhaps his dhcp setting is set to a small range like 101,102 only and therefore only has two assignable addresses.

I havent had that issue with the AT&T fiber 2wire unit since I don't use their wireless because it is limited to b/g only. I have a cisco router with wireless N running DD-WRT, and dual radios for 2.4/5ghz and have my ip range set for 100 a available dhcp addresses. I have on my system, at least 8 devices connecting via wifi and 3 via wired.

My Suggestion, check your router configuration. if it is isp limited to only one or two dhcp addresses, I would suggest trying to change it to allow more, or get your own router and let it use one of those ip's then broadcast out enough for your systems.

I know on my macs, they don't assign in order of available dhcp addresses. i.e. 101,102,103, etc. one of them is 134, one is 125, one is 102, etc.
 
This is definitely a router setting you need to fix. The best thing would be to set static IPs to each device and set a range outside of the set IPs for new devices that connect.
 
Thank you for the responses!!
Mostly, I have no idea what you guys are talking about but, I did figure out how to get into the router configurations and I changed the DHCP Maximum number of users to (pick an arbitrary number) 10.

Is that ok to pick an arbitrary number of DHCP users?

Also, I am using a WRTU54G-TM Hot Spot (T-Mobile) router connected to a Motorola Surfboard Extreme Cable Modem connected to Comcast. When you tell me to replace the router, give me your opinion about the best router under $100.

Thank you brop52, AshMan, and seveej!!
 
newomij said:
Thank you for the responses!!
Mostly, I have no idea what you guys are talking about but, I did figure out how to get into the router configurations and I changed the DHCP Maximum number of users to (pick an arbitrary number) 10.

Is that ok to pick an arbitrary number of DHCP users?

Also, I am using a WRTU54G-TM Hot Spot (T-Mobile) router connected to a Motorola Surfboard Extreme Cable Modem connected to Comcast. When you tell me to replace the router, give me your opinion about the best router under $100.

Thank you brop52, AshMan, and seveej!!
Click to expand...

Well lets try to work with what you have now. Are you sure the max wasn't defaulted at 50? 10 seems low.

Either way there should be some way to change the settings and set every computer/device on your network to have its own set IP address.
 
Unsure what the default number of DHCP users was. When I went in to the router settings, it was set to 2 so I upped it to 10 - more than I think I will ever need.

Setting each device to have it's own IP address? How will that be accomplished on these MacBooks?
 
Just out of curiosity check the MAC address on each machine. Ive never heard of it happen before but maybe they are the same?

Spotlight / Terminal and run the following...

Code: 
networksetup -listallhardwareports
 
newomij said:
Unsure what the default number of DHCP users was. When I went in to the router settings, it was set to 2 so I upped it to 10 - more than I think I will ever need.

Setting each device to have it's own IP address? How will that be accomplished on these MacBooks?
Click to expand...

You would actually do it through the router interface.
 
Can you give one IP address of one machine the subnet mask and the IP address of the router and we can probably just set te macs up manually.

What range is the router giving for the DCHP assignments?

Is the sprint rave and VOIP setup using DCHP or manual addressing?
 
When you upped the dhcp from 2 to 10, did that solve the issue?

tons of routers for under $100.00

I would recommend most anything but drink, had one that was horrible. never had issue with cisco/linksys, but my linksys runs custom dd-wrt firmware.
 
I apologize, I didn't go in to look at the mac addresses to see if they were the same on both machines. I assume that would be accomplished by going into the router settings from each machine?

After resetting the DHCP Users allowed from 2 to 10, that has alleviated the issues we were having regarding the original post.

I thank you all for helping us with this. I appreciate this forum and the responsiveness of this community.:)
 
newomij said:
I apologize, I didn't go in to look at the mac addresses to see if they were the same on both machines. I assume that would be accomplished by going into the router settings from each machine?

After resetting the DHCP Users allowed from 2 to 10, that has alleviated the issues we were having regarding the original post.

I thank you all for helping us with this. I appreciate this forum and the responsiveness of this community.:)
Click to expand...

Glad it works. Maybe your router isn't designed for multiple clients and perhaps that's why it was defaulted at 2. 2 is a very small number of clients at once to have.
 
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