[v4_1_esv] Add section on ports to client and server man pages

2 files changed, 50 insertions, 0 deletions

diff --git a/client/dhclient.8 b/client/dhclient.8
index fa7b1e69..5814c069 100644
--- a/client/dhclient.8
+++ b/client/dhclient.8
@@ -381,8 +381,28 @@ Path to the network configuration script invoked by
 when it gets a lease.  If unspecified, the default
 .B CLIENTBINDIR/dhclient-script
 is used.  See \fBdhclient-script(8)\fR for a description of this file.
+.PP
+.SH PORTS
+During operations the client may use multiple UDP ports
+to provide different functions.  Which ports are opened depends
+on both the way you compiled your code and the configuration you
+supply.  The following should provide you an idea of what
+ports may be in use.
+
+Normally a DHCPv4 client will open a raw UDP socket to receive
+and send most DHCPv4 packets.  It also opens a fallback UDP socket
+for use in sending unicast packets.  Normally these will both
+use the well known port number for BOOTPC.
 
+For DHCPv6 the client opens a UDP socket on the well known
+client port and a fallback UDP socket on a random port for
+use in sending unicast messages.  Unlike DHCPv4 the well
+known socket doesn't need to be opened in raw mode.
 
+If you have included an omapi port statement in your configuration
+file then the client will open a TCP socket on that port to
+listen for OMPAI connections.  When something connects another
+port will be used for the established connection.
 .PP
 .SH CONFIGURATION
 The syntax of the \fBdhclient.conf(5)\fR file is discussed separately.
diff --git a/server/dhcpd.8 b/server/dhcpd.8
index a56aee9f..f7e76c40 100644
--- a/server/dhcpd.8
+++ b/server/dhcpd.8
@@ -326,6 +326,36 @@ Option to disable writing pid files.  By default the program
 will write a pid file.  If the program is invoked with this
 option it will not check for an existing server process.
 .PP
+.SH PORTS
+During operations the server may use multiple UDP and TCP ports
+to provide different functions.  Which ports are opened depends
+on both the way you compiled your code and the configuration you
+supply.  The following should provide you an idea of what
+ports may be in use.
+
+Normally a DHCPv4 server will open a raw UDP socket to receive
+and send most DHCPv4 packets.  It also opens a fallback UDP socket
+for use in sending unicast packets.  Normally these will both
+use the well known port number for BOOTPS.
+
+For each DHCPv4 failover peer you list in the configuartion file
+there will be a TCP socket listening for connections on the
+ports specififed in the configuration file.  When the peer connects
+there will be another socket for the established connection.
+For the established connection the side (primary or secondary)
+opening the connection will use a random port.
+
+For DHCPv6 the server opens a UDP socket on the well known
+dhcpv6-server port.
+
+The server opens an icmp socket for doing ping requests to check
+if addresses are in use.
+
+If you have included an omapi-port statement in your configuration
+file then the server will open a TCP socket on that port to
+listen for OMPAI connections.  When something connects another
+port will be used for the established connection.
+.PP
 .SH CONFIGURATION
 The syntax of the dhcpd.conf(5) file is discussed separately.  This
 section should be used as an overview of the configuration process,