It only works if vlan_reorder is turned off to disable the vlan tag
removal.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
doc/payload-expression.txt | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/doc/payload-expression.txt b/doc/payload-expression.txt
index 106ff74ce57e..113f5bfc597c 100644
--- a/doc/payload-expression.txt
+++ b/doc/payload-expression.txt
@@ -23,6 +23,14 @@ VLAN HEADER EXPRESSION
[verse]
*vlan* {*id* | *dei* | *pcp* | *type*}
+The vlan expression is used to match on the vlan header fields.
+This expression will not work in the *ip*, *ip6* and *inet* families,
+unless the vlan interface is configured with the *reorder_hdr off* setting.
+The default is *reorder_hdr on* which will automatically remove the vlan tag
+from the packet. See ip-link(8) for more information.
+For these families its easier to match the vlan interface name
+instead, using the *meta iif* or *meta iifname* expression.
+
.VLAN header expression
[options="header"]
|==================
--
2.35.1
