The man page for zebra(8) mentions as port number to connect to 2602,
but it's acutally 2601 (as shown in /etc/services). 2602 belongs to ripd.
Attached patch fixes this typo.
.TP
\fB\-P\fR, \fB\-\-vty_port \fR\fIport-number\fR
Specify the port that the zebra VTY will listen on. This defaults to
-2602, as specified in \fB\fI/etc/services\fR.
+2601, as specified in \fB\fI/etc/services\fR.
.TP
\fB\-A\fR, \fB\-\-vty_addr \fR\fIvty-address\fR
Specify the address that the zebra VTY will listen on. Default is all