[Oisf-users] SEPTun and memory usage

Peter Manev petermanev at gmail.com
Thu Jul 13 12:13:11 UTC 2017

On Thu, Jul 13, 2017 at 1:57 PM, erik clark <philosnef at gmail.com> wrote:
> All, trying to find out who has worked with the SEPTun document that can
> provide some insight into how much memory they are using to sniff traffic.
> We (were) using 8 threads with 200 gigs of ram on a 2.5 Gb/s link. Until
> earlier this week, our drop rate was ~2%. I just moved up to 16 threads,
> still at 200 gigs of ram, since our throughput moved up a bit to ~3.1Gb/s
> and saw a 12% drop rate.
> We have 72 cores to work with, and 200 gigs of ram, and just moved to a 4.4
> kernel from a modified 3.10 kernel. What seems reasonable on this kind of
> hardware? We are limited to an 82598 ixgbe interface with a single link.

Seems very high memory consumption settings are in place in your case.

SEPTun utilized 64-80 GB of RAM on the 20Gbps. (we also used some
general guidance -
for getting the calculation of the total possible consumption).

Although sizeof(structPacket_) is much smaller now i believe - about 7-800bytes

What also your default packet size (in suricata.yaml) or the MTU ?
What is the otuput of -
suricata --dump-config |grep memcap
What is the ring size of the afpacket configuration?


Peter Manev

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