[Snort-users] flow:established still broken in 220.127.116.11?
Jason.Haar at ...294...
Wed Jun 29 18:12:33 EDT 2011
On 30/06/11 09:33, Russ Combs wrote:
> depth:2 applies to the current packet (raw or reassembled). It is not
> a depth from beginning of stream.
Ahhh! the penny drops - so it should be expected to get FPs due to this
then? Shouldn't there be a "streamdepth:" option then? Almost all TCP
protocols are defined by their first few bytes, so checking only the
beginning of a stream should improve things for many rules? I have
routinely seen FPs caused by this with SSL and ZIP/compressed data flows
- almost all would be removed if there was a "streamdepth" sort of option.
(I've just checked the manual and indeed "depth" is only about packets,
not streams - and yet all the "tcp_stream" options in snort had lead me
to believe it did something more precise - my mistake :-)
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