From: hannes <hannes>
Date: Sat, 9 Apr 2005 15:17:01 +0000 (+0000)
Subject: add documentation for hierarchical VLAN filtering in libpcap 0.9
X-Git-Tag: tcpdump-4.0.0~529
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/10721333c48fdc9b9505a14792629ce4226b07ca

add documentation for hierarchical VLAN filtering in libpcap 0.9
---

diff --git a/tcpdump.1 b/tcpdump.1
index 05991bda..ee7f7ad6 100644
--- a/tcpdump.1
+++ b/tcpdump.1
@@ -1,4 +1,4 @@
-.\" @(#) $Header: /tcpdump/master/tcpdump/Attic/tcpdump.1,v 1.167 2004-12-28 22:31:25 guy Exp $ (LBL)
+.\" @(#) $Header: /tcpdump/master/tcpdump/Attic/tcpdump.1,v 1.168 2005-04-09 15:17:01 hannes Exp $ (LBL)
 .\"
 .\"	$NetBSD: tcpdump.8,v 1.9 2003/03/31 00:18:17 perry Exp $
 .\"
@@ -998,6 +998,15 @@ If \fI[vlan_id]\fR is specified, only true is the packet has the specified
 Note that the first \fBvlan\fR keyword encountered in \fIexpression\fR
 changes the decoding offsets for the remainder of \fIexpression\fR
 on the assumption that the packet is a VLAN packet.
+the \fI[vlan_id]\fR statement may be used more than once, to filter on vlan hierarchies.
+each use of the \fI[vlan_id]\fR \fIexpression\fR increments the filter offsets by 4.
+.fi
+example(s):
+.fi
+"vlan 100 && vlan 200" filters on vlan 200 encapsulated within vlan 100
+.fi
+"vlan && vlan 300 && ip" filters IP protocols encapsulated in vlan 300 encapsulated within any higher order vlan
+.fi
 .IP  "\fBtcp\fR, \fBudp\fR, \fBicmp\fR"
 Abbreviations for:
 .in +.5i