Security Incidents mailing list archives
Re: An ICMP Type 3 Signature
From: Steffen Dettmer <steffen () dett de>
Date: Tue, 10 Oct 2000 23:03:21 +0200
* Stephen P. Berry wrote on Wed, Oct 04, 2000 at 13:26 -0700:
-Neither of the destination addresses (a.b.c.d and i.j.k.l in the above example) had sent any traffic to 194.102.148.213 in the two hours prior to receiving the ICMP datagrams (two hours is as far back as I looked---they've probably -never- sent anything to 194.102.148.213). In fact i.j.k.l was an unused address that wasn't sending or receiving -anything-
[...] Well, I experimented with ICMP messages when playing with a fast traceroute method. I made a tool that sends out a lot of UDP packets, and thus receiving a lot of ICMP time exeededs at "one" time, and from the included orginal UDP packets the tool builds the route path (like traceroute, but more faster; http://sws.dett.de/Simpletraceroute if anyone is interested in the sources). I found by that, that I receive sometimes a lot of malformed ICMP messages. They do include some data, but not the data from the UDP packet that was sent by simpletraceroute. I thought, that there may be broken TCP/IP implementations out there, so this may not a bullet-proof thing. So the addresses may be some "random" data; but really it surprised me a lot, that at least some of those included (old UDP) packets contained the right cksum! If anyone could explain that "strange behaivior" I would be very glad about an email (if offtopic for this list, please use PM). oki, Steffen -- Dieses Schreiben wurde maschinell erstellt, es trägt daher weder Unterschrift noch Siegel.
Current thread:
- An ICMP Type 3 Signature Stephen P. Berry (Oct 04)
- Re: An ICMP Type 3 Signature Russell Fulton (Oct 10)
- Re: An ICMP Type 3 Signature Steffen Dettmer (Oct 11)
- <Possible follow-ups>
- Re: An ICMP Type 3 Signature Donald McLachlan (Oct 05)
- Re: An ICMP Type 3 Signature Stephen P. Berry (Oct 10)
- Re: An ICMP Type 3 Signature Donald McLachlan (Oct 10)
- Re: An ICMP Type 3 Signature Stephen P. Berry (Oct 11)
- Re: An ICMP Type 3 Signature Jay Random (Oct 11)
- Re: An ICMP Type 3 Signature George Bakos (Oct 13)
- Re: An ICMP Type 3 Signature Jay Random (Oct 17)
- Re: An ICMP Type 3 Signature George Bakos (Oct 19)