Unanswered Question
Jul 30th, 2008

I don't quite understand the Destination Descriptors when writing a rule. For example, I'm checking the default "System Rule: Password Attacks: SNMP - Attempt" and under Destination IP there are these three descriptors "Same", "$Target01" and "Any". Are these overlapping?? Any means any IP. Doesn't fall into "same" IP descriptor?.

Also, "$Target01" means to me that same variable in another field has the same value. Isn't this the same as using "same" descriptor?

Not so clear.

I have this problem too.
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mhellman Wed, 07/30/2008 - 09:46

I can't answer why offsets have all three...makes no sense to me and I've always wondered why.

I can tell you the difference between $TARGET01 and SAME. the target variables are a way of matching outside of a single offset. So I can create an offset with a target01 variable, and then essentially refer to the matching IP address in a later offset. The SAME variable only matches within an offset.

I will illustrate using two "rules" below


1,same,event A,100

2,same,event B,10

1,target01,event A,100

2,target01,event B,10

The first offset in both rules will match 100 "events A" events with the same IP address, y.y.y.y. If 10 "event B" events are received all with ip address x.x.x.x, the second rule won't match but the first one will. Clear as mud?


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