Identical IPs: How common is it?

Identical IPs Need Help!

[Tafkac]

Hi everyone,
I'm a cpu savvy guy, but not too savvy on IPs. So I have question for you guys who know what they're talking about.

How common are identical IPS assigned from a service provider. For an example, On this Forum, what are the odds that if AOL is your ISP, that members here will have identical IPS/or share the same IPs,

And what are the odds more than one member of this board share like 4 identical IPs, and of course post at different times.

So can this be a common occurance on a board like this?
Is identical IPS so common that members on one Forum out the whole cyberspace can share identical IPS.

And if they members do share like, 4 identical IPS is it more likely that they are the same person, or that they were just simply assigned the same IPS.

Example:
Tom
Mike
bill
dave
Kevin all share 4 identical IPs on this board.

Is it more likly that these members are
A) the same person
b) more than one person using the same cpu
c) These are seperated individuals from around the globe that AOL coincidently assigned them the same 4 IPs

I would love to hear your knowledge and expertise on this subject. Please let me know what you think.
Thanks!

[Mardi_Gras]

Is identical IPS so common that members on one Forum out the whole cyberspace can share identical IPS.

Sure - it is entirely possible that users who share the same Internet Service Provider (if that ISP provides IP addresses dynamically) will sometime log in under the same IP address - but not at the same time.

I would think in a universe of 1,000,000 visitors that might be pretty common. In a universe of, say, 1,000, it would be much less common.

You may note that on this Board one needs cookies enabled to post - much more effective way of tracking users than IP addresses.

<<added>>I would think the odds of your example being a simple case of one IP address being innocently assigned to several different regular users of a small board are somewhere between slim and none.>>

[Tafkac]

Thanks so much Mardi_Gras

Even if the board has alil over 700 members will the odds be slim that around 4 guys share the same IPs?

and please I would love to hear from more
MUCH LOVE!

[bcc1234]

will sometime log in under the same IP address - but not at the same time.

Some ISPs user proxies, and that might look to the outside world like several users coming from the same IP at the same time.

[jimbeetle]

I think that any type of shared connection would look the same. If you have an office with 100 people on a T1 line and ten logged into a discussion board at the same it would all be from the same IP. Similarly if I logged in three machines here that share a DSL line.

At least I think so.

Jim

[Tafkac]

Thanks Jimbeetle!, but does that explain 4 people sharing 4 different IPs?

[FloydianLeaf]

I would like an answer to this as well.

I am a moderator at a message board and I have 4 members, all disruptive, one who has been banned before all coming up with the same IP address.

Completely identical.

All on the same thread, all posting back to back to back, all with the same IP address.

Poster "A"
66.185.84.***

Poster "B"
66.185.84.***

Poster "C"
66.185.84.***

Poster "D"
66.185.84.***

The "***'s" all being the same but hidden to protect their rights.

Seriously, how likely is this?

[bird]

AOL users don't access your server directly, they have to go through proxies. An arbitrary number of users will be routed through the same proxy at any one time. What makes things even worse is that AOL tends to rotate their users through several proxies during the same session. It is not uncommon that successive page requests by the same user come from different IPs.

In other words: With users coming from AOL, there is no clear correlation between a person and an IP address. What you see in your logs is *not* the IP assigned to the users machine at that time. That doesn't mean that those "several" visitors can't be the same person, just that the IP isn't giving you any solid indication. All you know for sure that they're coming through AOL.

The IPs in msg#:7 are not from AOL, but are connected through rogers.com cable service in chicago. I don't know about rogers, but many cable ISPs assign fixed IPs to their customers (they're always on anyway). In this situation, four posters with the same IP are much more likely to actually be the same person.

[mole]

> does that explain 4 people sharing 4 different IPs?

could do - any sort of connection sharing will allow more than one simultaneous user to appear to be from the same IP.

So if they're using a router set up to do NAT (Network Address Translation) or even a modem on a PC sharing its internet connection, they will all look as if they've all got the same IP.

Most dial-up and DSL connections will give you a different IP each time you conect.
I guess it would be a little odd if a DSL connection was being disconnected / reconnected very frequently. But it's still possible.

So yes, a group of several users all from the same simultaneous IP at the same time, then a little later from the same IP, but different from what is was before.

Possible, if my explanation makes sense.

[FloydianLeaf]

In my case all 4 users are coming up as Rogers cable customers, all from the same CO (Rogers 29) and all claim to have nothing to do with one another at all (in other words they don't work in the same place, know eachother or have any affiliation with one another)

Or so they (he?) claims.

[jimbeetle]

Haven't been around for a couple of days, thanks Mole for your excellent clarification of what I was trying to say.

In Tafkac's case it would really be hard to pin it down as to whether this is the same person or four different people, there are a lot of ways to play games with boards.

And in FloydianLeaf's problem, cable customers do share connections. I would 'assume' that these would be in the same local area so somewhere along the line his four people live or work near each other, whether they know it or not.

Coincidence that in both cases these are problem board members? Some people say there are no coincidences.

[FloydianLeaf]

Thanks.

I didn't know 4 users not on a network could use the same IP address.

Interesting.

[toadhall]

Floydianleaf,

> all 4 users are coming up as Rogers cable customers,...all claim to have nothing to do with one another

Did you compare host names or just IPs? It's my understanding Rogers issues unique host names to its high speed customers.

T

[FloydianLeaf]

How would I go about checking the host names?

Thanks in advance.

[toadhall]

I use PHP. The function is gethostbyaddr() [php.net]. Use it to extract the host name via the server's REMOTE_ADDR environment variable.

The host name is not always available so it's best to suppress error messages with @, and use a conditional statement when outputting it:

$host = @gethostbyaddr($REMOTE_ADDR);

if ($host) {
$loghost = ("Visitor's Host name: $host");
} else {
$loghost = ("Visitor's Host name: unavailable");
}

T

[neolithic]

sheesh! there are millions of ip's but unlike phone numbers there are only so many to go around, this is very common in the uk where there are only maybe 100 isp's and they all purchase ip's in blocks of say 10,000.
I supply web traffic to the uk and one you get more than 10,000 visits your unique/ip ratio is around 2 and we consider this a good ratio!

Mainly BT, NTL and Blueyonder, their ip's seem to be used by other smaller isp's too.

I believe the problem is better in bigger coninents like europe and usa, my usa logs show around 1.3 and this is cos we get a lot of AOL visitors so i guess they have a finite number too.
I did find a list of them but
A) its massive
B) its always out of date
C) you need a database query to undo the mess of it

You can resolve them back to the originating isp but i gave up as i deliver 3 million hits a month to each of 2 continents, now i let my customers do it if they want to.
95% don't care.

[toadhall]

FloydianLeaf,

I could be wrong about Rogers issuing unique hostnames to their users; the hostnames I've received from Rogers are so long and convoluted I've assumed they were. But they're cable, so it's altogether possible they're piggy-backing users on single IPs via their own sub-network (pardon my layman terminology).

Either they're 4 people on a Local Area Network in a business or institution or 4 machines running through a hub at a residence, or they're living close together in one section of town (as suggested) OR it's one person spamming your board.

Can you get any other user data - like browser type and version, screen resolution, OS - to narrow down their identities?

T

[edited by: toadhall at 9:32 pm (utc) on Jan. 27, 2003]

[FloydianLeaf]

I wouldn't even know where to start in getting that stuff. Of course they/he wouldn't help me out.

[FloydianLeaf]

This is what comes up on the IP check.

All greek to me. :o

OrgName: Rogers@Home
OrgID: ROGERS-29

NetRange: 66.185.80.0 - 66.185.95.255
CIDR: 66.185.80.0/20
NetName: ROGERS-CABLE-BACKBONE
NetHandle: NET-66-185-80-0-1
Parent: NET-66-0-0-0-0
NetType: Direct Assignment
NameServer: NS1.WLFDLE.RNC.NET.CABLE.ROGERS.COM
NameServer: NS2.WLFDLE.RNC.NET.CABLE.ROGERS.COM
NameServer: NS1.YM.RNC.NET.CABLE.ROGERS.COM
NameServer: NS2.YM.RNC.NET.CABLE.ROGERS.COM
Comment:
RegDate: 2001-11-01
Updated: 2001-11-15

TechHandle: AD30-ARIN
TechName: Budd, Paul
TechPhone: [phone]
TechEmail: [e-mail]

[Tafkac]

hey guys, me again. Thanks for the info.

Just to confirm some things. I know I'm ignorant but I hope to get smarter ha.

I have 3 guys in a forum that post with these 2 IP's ALL THE TIME.( I assume they are not using dial up)

EXAMPLE:

TOD) 777.777.777.777
666.666.666.666

Mike) 777.777.777.777
666.666.666.666

Dave) 777.777.777.777
666.666.666.666

They all use AOL and claim not to know each other.
Now if their IPs never change does this conclude dialup isn't being used? And does it conclude that they are using Broadband or on a network?

Now, I'm aware you guys said that AOL reuses IPs. But if the IPs of these individuals never change then aren't these guys either
ON the same network?(same building)
NOT using DIALUP?
The SAME PERSON?...

I apologize if I sound like I'm regurgitating info, but please enlighten me just a bit more with your knowledge.

Thanks guys much appreciative!