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Version: Tenzir v4.11

decapsulate

Decapsulates packet data at link, network, and transport layer.

Deprecated

This operator will soon be removed in favor of first-class support for functions that can be used in a variety of different operators and contexts.

Synopsis

decapsulate

Description

The decapsulate operator proceses events of type pcap.packet and decapsulates the packet payload by extracting fields at the link, network, and transport layer. The aim is not completeness, but rather exposing commonly used field for analytics.

The operator only processes events of type pcap.packet and emits events of type tenzir.packet.

VLAN Tags

While decapsulating packets, decapsulate extracts 802.1Q VLAN tags into the nested vlan record, consisting of an outer and inner field for the respective tags. The value of the VLAN tag corresponds to the 12-bit VLAN identifier (VID). Special values include 0 (frame does not carry a VLAN ID) and 0xFFF (reserved value; sometimes wildcard match).

Examples

Decapsulate packets from a PCAP file:

from file /tmp/trace.pcap read pcap
| decapsulate

Extract packets as JSON that have the address 6.6.6.6 as source or destination, and destination port 5158:

read pcap
| decapsulate
| where 6.6.6.6 && dport == 5158
| write json

Query VLAN IDs using vlan.outer and vlan.inner:

read pcap
| decapsulate
| where vlan.outer > 0 || vlan.inner in [1, 2, 3]

Filter packets by Community ID:

read pcap
| decapsulate
| where community_id == "1:wCb3OG7yAFWelaUydu0D+125CLM="