Messages in this thread | | | Date | Fri, 6 Oct 2000 23:16:34 +0200 | From | "Andi Kleen" <> | Subject | Re: ack number in a connection-refused RST |
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On Fri, Oct 06, 2000 at 09:06:31PM +0000, David Wagner wrote: > David S. Miller wrote: > >Linux should not honor the incorrect sequence number. If the sequence > >number is incorrect, the RST could legitimately be for another > >connection. > > How could it be for another connection, if it has source and destination > port numbers? I thought the sequence number was there to prevent denial > of service attacks, i.e., to prevent unauthorized third parties from > tearing down established TCP connections; since third parties will not > know (or be able to guess) the current 32-bit sequence number, they will > be unable to forge a valid RST packet. Of course, this argument is still > valid even if you accept off-by-one errors in the sequence number; the > attacker still has to guess from a 31-bit space, which is slightly smaller > than the original 32-bit space but still likely large enough for security. > What am I missing?
You're missing dynamic IPs, NAT and reboot of hosts.
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