Snort mailing list archives
Re: Performance again
From: Matt Kettler <mkettler () evi-inc com>
Date: Tue, 23 Dec 2003 11:24:11 -0500
At 10:55 AM 12/23/2003, Edin Dizdarevic wrote:
The first question is anyway, what is actually ment by the statistics? It would be interessting to know, in which stages of the process a packet drop may occur and what is ment by the output/perfmon: 1. During the capture (and copy from the kernel to the user space) 2. During the preprocessing/reassembling/decoding 3. During the pattern matching/alerting 4. During the output 5. Other?
5. Other.with libpcap, packets are queued into a buffer for snort to read. That buffer is a fixed size. When snort reads a packet, it is removed from the buffer and that space is freed for new packets to arrive.
If new packets arrive and the buffer is full, the old ones are dropped.Thus, a packet drop is not something that happens within any of the above stages, it happens when all of 2-4 aren't completed before 1 happens again.
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Current thread:
- Performance again Edin Dizdarevic (Dec 23)
- Re: Performance again Brian (Dec 23)
- Re: Performance again Edin Dizdarevic (Dec 23)
- Re: Performance again Matt Kettler (Dec 23)
- Re: Performance again Edin Dizdarevic (Dec 23)
- Re: Performance again Matt Kettler (Dec 23)
- Re: Performance again Lawrence Reed (Dec 23)
- Re: Performance again Edin Dizdarevic (Dec 23)
- Re: Performance again Matt Kettler (Dec 23)
- Re: Performance again Edin Dizdarevic (Dec 23)
- Re: Performance again Brian (Dec 23)