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Message-ID: <Pine.LNX.4.44.0412130925530.10480-100000@zolder.forfun.net>
From: mdavids at forfun.net (Marco Davids (Prive))
Subject: GPRS/IP-session from Nokia/Symbian mobile
phone stays up
On Tue, 7 Dec 2004, William Reading wrote:
> Howdy,
>
> I think this is part of the reason why some carriers, such as T-Mobile,
> use RFC1918 addresses instead of publically routable IPs.
Not here in the Netherlands :-)
inetnum: 194.229.200.0 - 194.229.207.255
netname: T-MOBILE-NL
descr: t-mobile.nl
country: NL
admin-c: RM1746-RIPE
tech-c: RM1746-RIPE
status: ASSIGNED PA
mnt-by: NLNET-MNT
changed: bartk@...uu.net 20030801
source: RIPE
I get an IP-address out of this range on my phone.
--
Marco
> They do allow
> you to specifically request real addresses if you need it for something
> like IPSec too. Of course, this is kind of a moot point when they have
> unlimited data plans in the US.
>
> William Reading
>
> Marco Davids (Prive) wrote:
>
> >Hi,
> >
> >For what it is worth:
> >
> >When my Nokia 6600 (Symbian V7.0s) mobile phone was connected to the
> >Internet and an imap-server for some tests the other day, I decided to
> >run a ping to the phone's IP-address (in fact I did an nmap -O to the
> >phone first, but that didn't work).
> >
> >After the mail was retrieved I closed the email-application on the phone.
> >Normally the GPRS-session is terminated in such a case. But not this time,
> >while the pings went on. This time I had to force the session to go down,
> >which is an option on the phone, luckily. I just never used it before :-)
> >
> >Later on I tried an SSH-session with the Mocha Telnet application from my
> >phone. Same behaviour. After I closed the SSH-application and as the
> >pings went on the (expensive) GPRS-session did not terminate as it
> >normally does when there is no incoming icmp traffic. When I finished
> >the external pings to the phone, the GPRS-session closed by itself.
> >
> >I tried again, this time with a larger packet-size, but that did not work.
> >
> >Then I tried a flood-ping and that did work. The GPRS-session stayed up
> >and the GRPS-counters increased dramatically! By this time my little
> >experiments where getting rather pricey for me.
> >
> >Conclusion: Even after the last application that uses IP on the phone is
> >closed, the GPRS-session stays up as long as there is incoming
> >(icmp)traffic. I am not sure what to think of this, but this seems
> >rather undesirable to me. Do other phones also 'suffer' form this
> >behaviour?
> >
> >This 'feature' can be abused. One could easily be lead to believe that the
> >GPRS-session is over, while in reality it is not.
> >
> >I did a quick ping-scan on the IP-range that my phone was in and
> >discovered 355 active, 'pingable', IP-addresses out of 2048. I figured it
> >be better not to start flood-pinging all of them them, but I couldn't help
> >thinking what would happen if some punk did: many phone's online would
> >probably stay online, depending on the number of phone models that show
> >the same behaviour. That would not only generate costs to their owners,
> >but would probaly also exhaust available IP-addresses for new
> >connections, resulting in some kind of DoS to the GPRS IP-service.
> >
> >Greetings,
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