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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: RFC3514
No the beauty of this is that it is declarative in nature. That means that unless there is some law saying that this transaction is different because it went over this protocol as opposed to that one. And although while Steve is clearly poking fun at the concept that one protocols is different from another - this is true and is becoming more so every day. So this is not so out of touch perhaps. Todd Glassey -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Owen DeLong Sent: Tuesday, April 01, 2003 9:22 AM To: Jack Bates; Scott Francis Cc: [email protected] Subject: Re: RFC3514 Hmmm.... Must be 4/1 again. Owen --On Tuesday, April 1, 2003 9:33 AM -0600 Jack Bates <[email protected]> wrote: > > Scott Francis wrote: >> Comments? >> >> (Nice to see Mr. Bellovin keeping up the holiday tradition ... :)) > Yep. > > " Fragments that by themselves are dangerous MUST have the evil bit > set. If a packet with the evil bit set is fragmented by an > intermediate router and the fragments themselves are not dangerous, > the evil bit MUST be cleared in the fragments, and MUST be turned > back on in the reassembled packet." > > There is no guidelines for specifying how the router will determine if > the fragments themselves are dangerous. An attacker may carefully design > the evil packet with the expectation of fragmentation, allowing the > fragments themselves to be the tool of the attack. It is therefore > recommended that all fragment of a packet with the evil bit set should > also have the evil bit set when fragmentation is performed by an > intermediate router incapable of determining the dangerous nature of the > packets. > > > :) > > -Jack >
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