019 might have disabled it for the same reason (security/DDOS)
אורי
u...@speedy.net


On Sun, May 19, 2024 at 6:08 PM Shlomo Solomon <shlomo.solo...@gmail.com>
wrote:

> Thanks.
>
> 1 - I will send it dirr=ectly to you - not to the list.
>
> 2 - No - that is not the problem since it works when I connect via a
> hotspot (i.e. a different ISP).
>
> When I use my "regular" 019 connection, I get:
> sudo python tmp1.py www.google.com
> 1 10.0.0.138 0.047
> 2 10.64.0.250 0.038
> 3 10.64.0.81 0.04
> 4 Timed Out
> 5 213.137.64.169 0.03
> 6 212.199.247.29 0.036
> 7 142.250.169.119 0.04
> 8 142.250.169.118 0.034
> 9 216.239.50.169 0.036
> 10 72.14.236.1 0.034
> 11 Timed Out
> 12 Timed Out
> 13 Timed Out
> 14 Timed Out
> 15 Timed Out
> 16 Timed Out
> 17 Timed Out
> 18 Timed Out
> 19 Timed Out
> 20 Timed Out
>
>
>
>
> When I connect via Hotspot (Golan), I get:
> sudo python tmp1.py www.google.com
> 1 192.168.43.85 0.054
> 2 Timed Out
> 3 172.25.86.33 0.136
> 4 172.25.50.130 0.042
> 5 172.27.27.2 0.062
> 6 172.27.27.6 0.058
> 7 207.232.57.110 0.062
> 8 207.232.57.183 0.06
> 9 72.14.197.132 0.038
> 10 142.251.229.3 0.086
> 11 72.14.236.1 0.058
> trace complete 12 172.217.22.100 0.056
>
> As you can see 72.14.236.1 is the last hop before reaching the
> destination, but on 019 all hops after that time out
>
>
>
>
>
>
>
> On Sun, 19 May 2024 17:49:32 +0300
> אורי <u...@speedy.net> wrote:
>
> > Hi Shlomo,
> >
> > 1. Send me the code and I will try to test it.
> > 2. Are you sure there is a reply when your message reaches the
> > destination? And does it depend on the destination? Some destinations
> > may disable it for security reasons (DDOS attacks).
> >
> > Uri.
> > אורי
> > u...@speedy.net
> >
> >
> > On Sun, May 19, 2024 at 5:43 PM Shlomo Solomon
> > <shlomo.solo...@gmail.com> wrote:
> >
> > > I teach computer networking and the latest assignment I gave my
> > > students was to use Python and Scapy to emmulate traceroute. The
> > > code is simple:
> > >  - send an ICMP packet with TTL = 1 which will fail but return the
> > > first hop address
> > >  - continue sending ICMP packets - each time increasing the TTL to
> > > get the next hop
> > >  - if the ICMP reply is NOT an error, we have arrived.
> > >
> > > None of my student submissions worked, which was strange, so I
> > > tried my own code which I know is correct.
> > > It also did not work.
> > > The error messages arrive for each hop, but it seems that the NO
> > > ERROR message (when the destination is reached) is not arriving.
> > > I also checked with Wireshark and see error replies (as I should)
> > > for each hop, but then (when I assume I have reached the
> > > destination) there is no reply.
> > >
> > > I then tried disconnecting my computer from my ISP and connected
> > > via a Hotspot on my phone - PROBLEM SOLVED.
> > >
> > > So this seems to be a problem with my ISP (019) blocking some
> > > traffic. But I don't know what the next step is.
> > > If I call customer service, I'm sure no-one will understand what I
> > > want.
> > >
> > > BTW - ping and the "real" traceroute work fine.
> > > I also looked at router settings, but did not find anything
> > > suspicious.
> > >
> > > Can anyone suggest how to explain my problem to my ISP?
> > >
> > > ALSO - if there is anyone using 019, I would be happy to send my
> > > code for testing to verify that this is really a problem with 019.
> > >
> > >
> > >
> > > --
> > > Shlomo Solomon
> > > http://the-solomons.net
> > > Claws Mail 4.0.0 - KDE Plasma 5.24.7 - Kubuntu 22.04
> > > _______________________________________________
> > > Linux-il mailing list -- linux-il@cs.huji.ac.il
> > > To unsubscribe send an email to linux-il-le...@cs.huji.ac.il
> > >
>
>
>
> --
> Shlomo Solomon
> http://the-solomons.net
> Claws Mail 4.0.0 - KDE Plasma 5.24.7 - Kubuntu 22.04
>
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