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.TH PCAP-LINKTYPE @MAN_MISC_INFO@ "7 April 2014"

.SH NAME

pcap-linktype \- link-layer header types supported by libpcap

.SH DESCRIPTION

For a live capture or ``savefile'', libpcap supplies, as the return

value of the

.BR pcap_datalink (3PCAP)

routine, a value that indicates the type of link-layer header at the

beginning of the packets it provides.  This is not necessarily the type

of link-layer header that the packets being captured have on the network

from which they're being captured; for example, packets from an IEEE

802.11 network might be provided by libpcap with Ethernet headers that

the network adapter or the network adapter driver generates from the

802.11 headers.  The names for those values begin with

.BR DLT_ ,

so they are sometimes called "DLT_ values".

.PP

The values stored in the link-layer header type field in the savefile

header are, in most but not all cases, the same as the values returned

by

.BR pcap_datalink() .

The names for those values begin with

.BR LINKTYPE_ .

.PP

The link-layer header types supported by libpcap are described at

https://www.tcpdump.org/linktypes.html.

.SH SEE ALSO

pcap(3PCAP)