+.
+.IP "\fBbundle(\fIfields\fB, \fIbasis\fB, \fIalgorithm\fB, \fIslave_type\fB, slaves:[\fIs1\fB, \fIs2\fB, ...])\fR"
+Hashes \fIfields\fR using \fIbasis\fR as a universal hash parameter, then
+applies the bundle link selection \fIalgorithm\fR to choose one of the listed
+slaves represented as \fIslave_type\fR. Currently the only supported
+\fIslave_type\fR is \fBofport\fR. Thus, each \fIs1\fR through \fIsN\fR should
+be an OpenFlow port number. Outputs to the selected slave.
+.IP
+Currently, \fIfields\fR must be either \fBeth_src\fR or \fBsymmetric_l4\fR and
+\fIalgorithm\fR must be one of \fBhrw\fR and \fBactive_backup\fR.
+.IP
+Example: \fBbundle(eth_src,0,hrw,ofport,slaves:4,8)\fR uses an Ethernet source
+hash with basis 0, to select between OpenFlow ports 4 and 8 using the Highest
+Random Weight algorithm.
+.IP
+Refer to \fBnicira\-ext.h\fR for more details.