Does the "-z" option mean you can't do "trigger on SYN"?

[Jason Haar <Jason.Haar () trimble co nz>]

I've got rules such as:

alert tcp $NET any -> $OTHER any (flags:S;...)

If I run with the "-z" option, that never triggers, but it does without.

If I use "-z" and change the alert to either:

flow:stateless;flags:S

or

flow:no_stream;flags:S

it still doesn't trigger.

Any ideas what the magic combo is? I'd rather use the "-z" option to protect
Snort from DoS style attacks, etc.

Redhat and snort 1.9.1

-- 
Cheers

Jason Haar
Information Security Manager, Trimble Navigation Ltd.
Phone: +64 3 9635 377 Fax: +64 3 9635 417
PGP Fingerprint: 7A2E 0407 C9A6 CAF6 2B9F 8422 C063 5EBB FE1D 66D1


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