Hi I agree, NAT is supposed to be almost impossible to detect. Change your dial-in password now and see what happens next billing cycle? Perhaps your mate who you helped to setup his computer will ring you later this week to tell you the Internet connection you helped him with has stopped working? Of course I have done that before. Gund -----Original Message----- From: James Clark [mailto:jamesc(a)bofh.co.nz] Sent: Fri 19/11/2004 12:04 To: Waikato Linux Users Group Cc: Subject: Re: [wlug] Overlapping usage nonsense On Fri, Nov 19, 2004 at 11:17:58AM +1300, Jared Wigmore wrote: > Having got a network and Internet connection sharing > set up (thanks Bruce), Xtra is now charging my family > for "overlapping usage" via my Linux computer. (The > Internet connection is on the family computer, with > Windows XP professional.) Overlapping usage: http://www.xtra.co.nz/help/0,,6155-1452314,00.html (if the link works) I suspect someone is dialling up with your account simultaniously, not because your NAT-ing... James. _______________________________________________ wlug mailing list | wlug(a)list.waikato.ac.nz Unsubscribe: http://list.waikato.ac.nz/mailman/listinfo/wlug
Gund Wehsling wrote:
Hi
I agree, NAT is supposed to be almost impossible to detect.
Change your dial-in password now and see what happens next billing cycle? Perhaps your mate who you helped to setup his computer will ring you later this week to tell you the Internet connection you helped him with has stopped working?
That would be me :) But I'm not using their dialup; on the rare occation that I need a dialup account I just steal Lindsay's :) Good advice though.
zcat wrote:
Gund Wehsling wrote:
Hi
I agree, NAT is supposed to be almost impossible to detect.
Change your dial-in password now and see what happens next billing cycle? Perhaps your mate who you helped to setup his computer will ring you later this week to tell you the Internet connection you helped him with has stopped working?
That would be me :) But I'm not using their dialup; on the rare occation that I need a dialup account I just steal Lindsay's :)
Hmm, sucks to be dyslexic, I misread that.. My other thought is that it's near-impossible to phone the Wigmore household a lot of the time and they probably should consider getting ADSL anyhow! $88 for the modem at DSE, and the cheaper plans (fine for basic browsing, no good for p2p) are not much different from the cost of dialup these days.
Hi
I agree, NAT is supposed to be almost impossible to detect.
Change your dial-in password now and see what happens next billing cycle? Perhaps your mate who you helped to setup his computer will ring you later
Hi, One way that NAT is often detectable is by looking at the TTL of packets from the one IP address, almost all packets coming from one system should have the same TTL, the nat'd machine will have a different TTL as it has to go an extra hop. Find it unlikely they are using that to determine multiple machine and would also suggest what Gund did re changing the dial-in password. If they are using that and using a linux machine as your gateway it is easy to overcome by using iptables to change the TTL on packets leaving the network to have the same TTL. Regards, Steve ----- Original Message ----- From: "Gund Wehsling" <Gund.Wehsling(a)computerland.co.nz> To: "Waikato Linux Users Group" <wlug(a)list.waikato.ac.nz>; "Waikato Linux Users Group" <wlug(a)list.waikato.ac.nz> Sent: Friday, November 19, 2004 10:51 AM Subject: RE: [wlug] Overlapping usage nonsense this week to tell you the Internet connection you helped him with has stopped working?
Of course I have done that before.
Gund
-----Original Message----- From: James Clark [mailto:jamesc(a)bofh.co.nz] Sent: Fri 19/11/2004 12:04 To: Waikato Linux Users Group Cc: Subject: Re: [wlug] Overlapping usage nonsense
On Fri, Nov 19, 2004 at 11:17:58AM +1300, Jared Wigmore wrote:
Having got a network and Internet connection sharing set up (thanks Bruce), Xtra is now charging my family for "overlapping usage" via my Linux computer. (The Internet connection is on the family computer, with Windows XP professional.)
Overlapping usage: http://www.xtra.co.nz/help/0,,6155-1452314,00.html (if the link works)
I suspect someone is dialling up with your account simultaniously, not because your NAT-ing...
James.
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Steven Lisson wrote:
Hi,
One way that NAT is often detectable is by looking at the TTL of packets from the one IP address, almost all packets coming from one system should have the same TTL, the nat'd machine will have a different TTL as it has to go an extra hop.
Find it unlikely they are using that to determine multiple machine and would also suggest what Gund did re changing the dial-in password.
If they are using that and using a linux machine as your gateway it is easy to overcome by using iptables to change the TTL on packets leaving the network to have the same TTL.
Regards, Steve
I would say that more than likely Gund is right.. Basically, my understanding of internet usage billing on dialup accounts is using a AAA server such as a TACACS+ or more likely a RADIUS server, and all the authentication server is interested in, is who you are, what you are allowed to do, and how long you have been authenticated. The fact that Xtra dialup accounts work on time based charging reflects the fact that they use this model. I can clearly see why Telecom charge for overlapping, one is so that a group of people don't decide to get an account and go halves with the cost (split it four ways, or whatever) and use the same dial in access collectively, and the other is so that someone doesn't try to do multi-linking (have two or more connections) in order to download/upload faster for the price of one connection - the provision for multi-linking would be there for ISDN users who wouldn't mind paying for overlapping usage. Basically, my intial reaction would be that someone has stolen (or at least inadvertantly using) you internet account and would do what Gund recommened.
On Fri, 2004-11-19 at 13:51, Gund Wehsling wrote:
Hi
I agree, NAT is supposed to be almost impossible to detect.
Change your dial-in password now and see what happens next billing cycle? Perhaps your mate who you helped to setup his computer will ring you later this week to tell you the Internet connection you helped him with has stopped working?
Of course I have done that before.
Gund
-----Original Message----- From: James Clark [mailto:jamesc(a)bofh.co.nz] Sent: Fri 19/11/2004 12:04 To: Waikato Linux Users Group Subject: Re: [wlug] Overlapping usage nonsense
On Fri, Nov 19, 2004 at 11:17:58AM +1300, Jared Wigmore wrote:
Having got a network and Internet connection sharing set up (thanks Bruce), Xtra is now charging my family for "overlapping usage" via my Linux computer. (The Internet connection is on the family computer, with Windows XP professional.)
Overlapping usage: http://www.xtra.co.nz/help/0,,6155-1452314,00.html (if the link works)
I suspect someone is dialling up with your account simultaniously, not because your NAT-ing...
This might be relevant, for people not on the NZNOG mailing list: http://list.waikato.ac.nz/pipermail/nznog/2004-December/009293.html Basically, there have been on-going problems with some RADIUS servers that do the dial-up accounting, so maybe that's why the ISP thinks your account was being used by multiple users at the same time... John
participants (5)
-
Gund Wehsling -
John R. McPherson -
Lindsay Druett -
Steven Lisson -
zcat