diff --git a/doc/userguide/performance/ignoring-traffic.rst b/doc/userguide/performance/ignoring-traffic.rst index 6e6f0db9f5..01bef3197d 100644 --- a/doc/userguide/performance/ignoring-traffic.rst +++ b/doc/userguide/performance/ignoring-traffic.rst @@ -1,9 +1,10 @@ Ignoring Traffic ================ -In some cases there are reasons to ignore certain traffic. Maybe a -trusted host or network, or a site. This document lists some -strategies for ignoring traffic. +In some cases there are reasons to ignore certain traffic. Certain hosts +may be trusted, or perhaps a backup stream should be ignored. + +This document lists some strategies for ignoring traffic. capture filters (BPF) --------------------- @@ -15,6 +16,25 @@ filter 'tcp' will only send tcp packets. If some hosts and or nets need to be ignored, use something like "not (host IP1 or IP2 or IP3 or net NET/24)". +Example:: + + not host 1.2.3.4 + +Capture filters are specified on the commandline after all other options:: + + suricata -i eth0 -v not host 1.2.3.4 + suricata -i eno1 -c suricata.yaml tcp or udp + +Capture filters can be set per interface in the pcap, af-packet, netmap +and pf_ring sections. It can also be put in a file:: + + echo "not host 1.2.3.4" > capture-filter.bpf + suricata -i ens5f0 -F capture-filter.bpf + +Using a capture filter limits what traffic Suricata processes. So the +traffic not seen by Suricata will not be inspected, logged or otherwise +recorded. + pass rules ---------- @@ -28,7 +48,7 @@ Example: pass ip 1.2.3.4 any <> any any (msg:"pass all traffic from/to 1.2.3.4"; sid:1;) -A big difference with capture filters is that logs such as http.log +A big difference with capture filters is that logs such as Eve or http.log are still generated for this traffic. suppress