.IP
When \fBdl_type\fR and \fBnw_proto\fR take other values, the values of
these settings are ignored (see \fBFlow Syntax\fR above).
-.IP \fBtun_id=\fItunnel\-id\fR
-Matches tunnel identifier \fItunnel\-id\fR. Only packets that arrive
+.IP \fBtun_id=\fItunnel-id\fR[\fB/\fImask\fR]
+Matches tunnel identifier \fItunnel-id\fR. Only packets that arrive
over a tunnel that carries a key (e.g. GRE with the RFC 2890 key
-extension) will have a nonzero tunnel ID.
+extension) will have a nonzero tunnel ID. If \fImask\fR is omitted,
+\fItunnel-id\fR is the exact tunnel ID to match; \fImask\fR is
+specified, then a 1-bit in \fImask\fR indicates that the corresponding
+bit in \fItunnel-id\fR must match exactly, and a 0-bit wildcards that
+bit.
.IP
\fBtun_id\fR requires use of one of two Nicira extensions to OpenFlow:
.RS
.IP "NXM (Nicira Extended Match)"
This extension fully supports \fBtun_id\fR.
.IP "Tunnel ID from Cookie"
-This extension supports \fBtun_id\fR with two caveats: the top 32 bits
-of the \fBcookie\fR (see below) are used for \fItunnel\-id\fR and thus
-unavailable for other use, and specifying \fBtun_id\fR on
-\fBdump\-flows\fR or \fBdump\-aggregate\fR has no effect.
+This extension supports \fBtun_id\fR with three caveats: the top 32 bits
+of the \fBcookie\fR (see below) are used for \fItunnel-id\fR and thus
+unavailable for other use, specifying \fBtun_id\fR on
+\fBdump\-flows\fR or \fBdump\-aggregate\fR has no effect, and
+\fImask\fR is not supported.
.RE
.IP
When \fBtun_id\fR is specified, \fBovs\-ofctl\fR will automatically
.IP
Example: \fBload:55\->NXM_NX_REG2[0..5]\fR loads value 55 (bit pattern
\fB110111\fR) into bits 0 through 5, inclusive, in register 2.
+.
+.IP "\fBmultipath(\fIfields\fB, \fIbasis\fB, \fIalgorithm\fB, \fIn_links\fB, \fIarg\fB, \fIdst\fB[\fIstart\fB..\fIend\fB])\fR"
+Hashes \fIfields\fR using \fIbasis\fR as a universal hash parameter,
+then the applies multipath link selection \fIalgorithm\fR (with
+parameter \fIarg\fR) to choose one of \fIn_links\fR output links
+numbered 0 through \fIn_links\fR minus 1, and stores the link into
+\fIdst\fB[\fIstart\fB..\fIend\fB]\fR, which must be an NXM register as
+described above.
+.IP
+Currently, \fIfields\fR must be either \fBeth_src\fR or
+\fBsymmetric_l4\fR and \fIalgorithm\fR must be one of \fBmodulo_n\fR,
+\fBhash_threshold\fR, \fBhrw\fR, and \fBiter_hash\fR. Only
+the \fBiter_hash\fR algorithm uses \fIarg\fR.
+.IP
+Refer to \fBnicira\-ext.h\fR for more details.
.RE
.
.IP