My IP Address in my college network is constantly taken away..

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
i'm running snow leopard on macbook pro.

my college has free internet access and every hostel has different IP addresses assigned. my hostel has this IP address 10.165.x.x

the students keep changing their IP address and somehow my macbook pro disables me from accessing the internet when a windows OS user in the network uses the same as mine.

Somehow windows OS doesn't allow the second user to use if its already taken but my poor mac OS allows it even while m using and i'll be thrown out. i'll have to look out for a new ip address which is not taken already.

any help as to how i can protect my own IP address?
 

maflynn

Moderator
Staff member
May 3, 2009
63,851
30,367
Boston
you can't since you're provided the IP address by the DHCP server. Just issue a release renew to get a new IP address. Perhaps running a script in the morning to achieve this would be the safest approach.
 

jpyc7

macrumors 6502
Mar 8, 2009
276
0
Denver, CO
Are you configured to use DHCP? From your post, it almost sounds like you might be searching for an unused IP and then assigning it to your Mac statically. If so, you cannot do that and expect to keep that IP. You will need to use DHCP.
 
Well it is not just depending on which OS you are running. That will happen all the time since it is not possible for 2 devices to have the same IP. Whenever this happens just renew the IP and you will be good unless you have a static IP and then you should tell the system admins of the school.
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
looks like you guys missed out something. IP address is "manually" configured: 10.165.x.x

For example, a student in the same hostel (windows 7) has this IP address running: 10.165.1.222 and if i try to use the same IP address in my macbook pro, there's a conflict and i will be asked to try another IP address. (this is good).

But then the problem is, If I have this IP address, say, 10.165.1.210, anyone in the hostel can use this IP address. When someone manually configures this IP address, I will get a warning saying that there's an IP conflict and I'll be kick out! They (windows' user) will not be asked to try another IP address as in my case.

hope you guys understood this time. thanx
 

maflynn

Moderator
Staff member
May 3, 2009
63,851
30,367
Boston
Why are you manually assigning IP addresses and not using a DHCP server? All of this would be avoided if you don't need to manually edit the IP addr
 

yg17

macrumors G5
Aug 1, 2004
14,888
2,480
St. Louis, MO
Use DHCP. Back when I was working at a college IT department, manually assigning an IP was a great way to get a nice talk with the IT security guys.
 

jpyc7

macrumors 6502
Mar 8, 2009
276
0
Denver, CO
looks like you guys missed out something. IP address is "manually" configured: 10.165.x.x

For example, a student in the same hostel (windows 7) has this IP address running: 10.165.1.222 and if i try to use the same IP address in my macbook pro, there's a conflict and i will be asked to try another IP address. (this is good).

But then the problem is, If I have this IP address, say, 10.165.1.210, anyone in the hostel can use this IP address. When someone manually configures this IP address, I will get a warning saying that there's an IP conflict and I'll be kick out! They (windows' user) will not be asked to try another IP address as in my case.

hope you guys understood this time. thanx
In this case, the best you can do is ask the school network administrators to find the offending person and get them to stop. There might be some setting in OS X to ignore the warning, but what good does that do you if you start to lose packets?
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
i was hoping to get help from all the mac geeks here and not criticize about the way the administration functions.

its not allowed in windows OS and so why is it allowed in mac OS? yeah m sure there's a setting out there somewhere to disable others from taking my IP address while m using it but i can't find it.
 

aristobrat

macrumors G5
Oct 14, 2005
12,244
1,312
What's the point?

If your Mac didn't give up the IP address, then you'd still have problems because two systems on the same subnet have the same IP address. Packets will get lost and things will start having problems.

There is no technical fix for this situation. You need an administrative fix. Either everyone uses dhcp or come up with a way to properly use static ips.
 

smogsy

macrumors 6502a
Jan 8, 2008
579
0
i had this exact problem at home,

after a long investigation i found out the ethernet ports where not giving me correct DCHP Information but Wifi was. i changed the router and all was well on all Win/Mac computers.

could be the same for you but the other way around :(
 

rroach3753

macrumors member
Nov 6, 2008
43
10
i'm running snow leopard on macbook pro.

my college has free internet access and every hostel has different IP addresses assigned. my hostel has this IP address 10.165.x.x

the students keep changing their IP address and somehow my macbook pro disables me from accessing the internet when a windows OS user in the network uses the same as mine.

Somehow windows OS doesn't allow the second user to use if its already taken but my poor mac OS allows it even while m using and i'll be thrown out. i'll have to look out for a new ip address which is not taken already.

any help as to how i can protect my own IP address?
We all understand what you are saying, everyone is trying to help. Maybe what should be asked is: Your Dorm is assigned 10.165.x.x as it's subnet, Were you assigned a specific IP Address by your college?

To clarify: You cannot "protect" an IP Address assigned to you on your own. You would have to report the problem to your college help desk. Windows also tells the user that a conflict has been encountered when someone assigns an IP to a machine that is already in use. It shows up in the lower right corner by the clock and a user can ignore the message if he/she wants too and continue to work and in 99.9% of the cases issues connecting will arise on both computers. Whether they are PC/Mac, PC/PC or MAC/MAC...it doesn't matter, its standard networking rule...Two house on the same street can't have the same mailing address can they?

Common practice would tell me and the rest of us trying to help you would say that you are not supposed to be assigning your Macbook a Static IP. Instead, letting DHCP do the work. Give it a try and see if you have any further errors.

Rickey
Net+, Windows Network Administrator, MS Exchange Administrator
 

gnasher729

macrumors P6
Nov 25, 2005
16,504
3,099
i was hoping to get help from all the mac geeks here and not criticize about the way the administration functions.

its not allowed in windows OS and so why is it allowed in mac OS? yeah m sure there's a setting out there somewhere to disable others from taking my IP address while m using it but i can't find it.
If your schools policy is to dynamically assign IP addresses then all computers that use DHCP will have IP addresses that change a lot, but they will all be different. Everyone who insists on using a static IP address will not be using the IP address they are assigned but the one they insist on to use. And as soon as the school dynamically assigns that IP address to someone else, there is trouble.

I think it might actually be you who is the trouble maker. And lots of other people (both Mac and Windows users) will occasionally have problems because of your computer.
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
We all understand what you are saying, everyone is trying to help. Maybe what should be asked is: Your Dorm is assigned 10.165.x.x as it's subnet, Were you assigned a specific IP Address by your college?

To clarify: You cannot "protect" an IP Address assigned to you on your own. You would have to report the problem to your college help desk. Windows also tells the user that a conflict has been encountered when someone assigns an IP to a machine that is already in use. It shows up in the lower right corner by the clock and a user can ignore the message if he/she wants too and continue to work and in 99.9% of the cases issues connecting will arise on both computers. Whether they are PC/Mac, PC/PC or MAC/MAC...it doesn't matter, its standard networking rule...Two house on the same street can't have the same mailing address can they?

Common practice would tell me and the rest of us trying to help you would say that you are not supposed to be assigning your Macbook a Static IP. Instead, letting DHCP do the work. Give it a try and see if you have any further errors.

Rickey
Net+, Windows Network Administrator, MS Exchange Administrator
its true. there can be no two IP addresses running at the same time. what i'm trying to say is, when i'm using an IP address, a windows user tries out the same IP address as mine, I would be thrown out. while in windows OS, if someone tries to use the same IP address, the current user still retains it and can simply ignore that balloon popup.

DHCP isn't the solution. talking to the institute's help desk is fruitless since m among the very very very few mac users. windows has NO issue whatsoever.
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
Picture 1.jpg shows when another user changes his IP address using windows OS, I'll be thrown out without a warning. the only solution: change my IP address manually again.
Please please note that in windows OS, the current user will just get a balloon warning but won't be thrown out.

Picture 2.jpg shows when i try to connect to an IP address which is already taken by another user in the hostel. (this is just to show you. no issue)
 

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Dark Dragoon

macrumors 6502a
Jul 28, 2006
843
3
UK
Why isn't DHCP the solution?
If you've tried it, what's the problem with it?

Pretty much every large network I've seen, and all the ones at several universities use DHCP, some with static assignment. When you first went to connect to the network were you told what settings to use?
Did they specifically tell you to use a static IP and to set it yourself?

I've had a similar situation while staying in uni accommodation where my Windows computers (didn't have a Mac at the time) connection would get messed up when someone tried to manually set their IP address to the same as mine, which was dynamically assigned via DHCP. I just had to release and renew to get a new address.
 
Picture 1.jpg shows when another user changes his IP address using windows OS, I'll be thrown out without a warning. the only solution: change my IP address manually again.
Please please note that in windows OS, the current user will just get a balloon warning but won't be thrown out.

Picture 2.jpg shows when i try to connect to an IP address which is already taken by another user in the hostel. (this is just to show you. no issue)
I understand your concern in trying to find out the difference but there is no real reason for that. It does not matter what operating you are running if two devices are using the same IP. If the individual IP addresses are assigned to each individual student then someone obviously has used your IP and you should report that to the Network Admins. They can resolve the issue and find who may or may not be the culprit for snatching your IP. Although if the school is using DHCP there should absolutely be NO STATIC IP's on the network other than the ones set by the admins. Even though they may be Mac illiterate, the best way to resolve it would be talk to the admins. They can do stuff that you may not even realize.
 

HenryAZ

macrumors 6502a
Jan 9, 2010
605
97
South Congress AZ
its true. there can be no two IP addresses running at the same time. what i'm trying to say is, when i'm using an IP address, a windows user tries out the same IP address as mine, I would be thrown out. while in windows OS, if someone tries to use the same IP address, the current user still retains it and can simply ignore that balloon popup.
It seems to me that OS X is being the intelligent OS here, by "throwing you out". The Windows user may choose to ignore the balloon and continue on in the face of an IP conflict, but they will have problems as long as the conflict exists.
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
@above
exactly. thats the problem. students keep changing their IP addresses! (For Heaven's sake, please don't ask me why? lol.. some of you are being weird hehe.. no offense though. i appreciate your reply and trying to help.)

It seems to me that OS X is being the intelligent OS here, by "throwing you out". The Windows user may choose to ignore the balloon and continue on in the face of an IP conflict, but they will have problems as long as the conflict exists.
Wrong answer. Windows OS shows you that there's an IP conflict to User1 but then refuses connection to user2 who tries to use the same IP address. Mac can't do this.

(by conflict, i mean there's another person (user2) trying to connect but user2 won't be able to connect since its already being used by user1. note that user1 is a windows OS user. If user1 had been on mac OS like in my case, user2 would have taken over user1. user1 would have to search for a new IP address)
 

calderone

macrumors 68040
Aug 28, 2009
3,678
83
Seattle
If students keep changing their addressess you need to report this to telecom. There is nothing anyone can do for you here.

It doesn't matter if it is Mac or Windows, the telecom department does not generally want people grabbing static addresses.
 

Dark Dragoon

macrumors 6502a
Jul 28, 2006
843
3
UK
So your college only does static and not DHCP assigned?
An answer to this question would be useful.

aningbo, are you sure that your hostel's network does not use DHCP and everyone has to setup static addresses on their computers?
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
i have been staying here for the last 3 years and sure its been this way long before i came. i've been using mac for about 9 months now.

students can manually use this IP address like this: 10.156.x.y where x ranges from 0-1 and y ranges from 1-250

@calderone
all this time, i have been trying to explain that this happens only in mac. windows os somehow manages to block people from using the manually assigned IP address. mac just kicks me out in the wild even while m using it.

No. my college doesn't use DHCP in the hostels except in the wifi zone.
 

chrono1081

macrumors 604
Jan 26, 2008
7,432
1,401
Isla Nublar
DHCP isn't the solution. talking to the institute's help desk is fruitless since m among the very very very few mac users. windows has NO issue whatsoever.
DHCP IS the solution and windows DOES have issues, you just arent seeing them.

If two devices on the same network have the same IP they will conflict. Trust me I do this for a living on networks with all win machines. There is no way around it. Like others have said its standard networking.

If the campus isn't using DHCP thats honestly just stupid. Static IPs can be used to circumvent all kinds of things. Unfortunately the only way around this is to talk to the staff. They need to make changes on their end of the network. If they are trying to tell you that its your mac that is the problem then they really shouldn't be doing the job they are doing because they have no clue what they are doing.
 

aningbo

macrumors member
Original poster
Sep 15, 2009
30
0
obviously they will conflict. i never said it won't. Same IP address will have conflict no matter which OS it is. you miss my very very important point though. please read carefully this time.

In windows, if the user1 has IP address 10.156.1.222 and user2 tries to use the same IP address, user1 will be notified (balloon tip) stating that there's a user trying to connect to the same IP address. nothing happens to the user1 in windows OS. he will NOT be kicked out. While the user2 will be notified at the same time that someone else is already using the IP address and user2 needs to find another IP address.

But in Mac OS given the same circumstance, user1 (mac user) will be kicked out with the warning (see screenshot above) and user2 will take over the IP address.

Is this really that hard to understand?

trust me, i have spoken to the staff and everyone i could think of. they just don't care. almost everyone uses windows os here.