Document new parameters.

diff --git a/server/dhcpd.conf.5 b/server/dhcpd.conf.5
index e76f210b647e94b53ae7d8f3039fe5ec40a0786b..8cddf00f6093afef4493b1a6be633191af0cc3bc 100644 (file)
--- a/server/dhcpd.conf.5
+++ b/server/dhcpd.conf.5
@@ -1898,6 +1898,27 @@ of the configuration file.
 .RE
 .PP
 The
+.I ping-checks
+statement
+.RS 0.25i
+.PP
+.B ping-checks
+.I flag\fR\fB;\fR
+.PP
+When the DHCP server is considering dynamically allocating an IP
+address to a client, it first sends an ICMP Echo request (a \fIping\fR)
+to the address being assigned.   It waits for a second, and if no
+ICMP Echo response has been heard, it assigns the address.   If a
+response \fIis\fR heard, the lease is abandoned, and the server does
+not respond to the client.
+.PP
+This \fIping check\fR introduces a one-second delay in responding to
+DHCPDISCOVER messages, which can be a problem for some clients.   The
+ping-checks configuration parameter can be used to control checking -
+if its value is false, no ping check is done.
+.RE
+.PP
+The
 .I server-identifier
 statement
 .RS 0.25i
@@ -1979,6 +2000,24 @@ only affects the behaviour of the \fIinterim\fR DDNS update scheme,
 and has no effect on the \fIad-hoc\fI DDNS update scheme.
 .PP
 The
+.I update-static-leases
+statement
+.RS 0.25i
+.PP
+.B update-static-leases \fIflag\fB;\fR
+.PP
+The \fIupdate-static-leases\fR flag, if enabled, causes the DHCP
+server to do DDNS updates for clients even if those clients are being
+assigned their IP address using a \fIfixed-address\fR statement - that
+is, the client is being given a static assignment.   This can only
+work with the \fIinterim\fR DDNS update scheme.   It is not
+recommended because the DHCP server has no way to tell that the update
+has been done, and therefore will not delete the record when it is not
+in use.   Also, the server must attempt the update each time the
+client renews its lease, which could have a significant performance
+impact in environments that place heavy demands on the DHCP server.
+.PP
+The
 .I use-host-decl-names
 statement
 .RS 0.25i