Update documentation of --force-dpd to reflect its new behavior

Signed-off-by: Daniel Lenski <dlenski@gmail.com>

diff --git a/main.c b/main.c
index b0b44fe3fe06e8ecc8b7e49326c61cf642dff053..9034e5c718a2542fa94e0ede9f9a688c21ea729d 100644 (file)
--- a/main.c
+++ b/main.c
@@ -939,7 +939,7 @@ static void usage(void)
        printf("      --base-mtu=MTU              %s\n", _("Indicate path MTU to/from server"));
        printf("  -d, --deflate                   %s\n", _("Enable stateful compression (default is stateless only)"));
        printf("  -D, --no-deflate                %s\n", _("Disable all compression"));
-       printf("      --force-dpd=INTERVAL        %s\n", _("Set minimum Dead Peer Detection interval (in seconds)"));
+       printf("      --force-dpd=INTERVAL        %s\n", _("Set Dead Peer Detection interval (in seconds)"));
        printf("      --pfs                       %s\n", _("Require perfect forward secrecy"));
        printf("      --no-dtls                   %s\n", _("Disable DTLS and ESP"));
        printf("      --dtls-ciphers=LIST         %s\n", _("OpenSSL ciphers to support for DTLS"));

diff --git a/openconnect.8.in b/openconnect.8.in
index 497ff3b70793f8ffa8b147500fb85659482ee4c1..882d2f26028c2bb7833dcd2def90d359e4fcba48 100644 (file)
--- a/openconnect.8.in
+++ b/openconnect.8.in
@@ -185,7 +185,14 @@ compression can be disabled by setting the mode to
 .B \-\-force\-dpd=INTERVAL
 Use
 .I INTERVAL
-as minimum Dead Peer Detection interval (in seconds) for CSTP and DTLS, forcing use of DPD even when the server doesn't request it.
+as Dead Peer Detection interval (in seconds). This will cause the client to use
+DPD at the specified interval even if the server hasn't requested it, or at a
+different interval from the one requested by the server.
+
+DPD mechanisms vary by protocol and by transport (TLS or DTLS/ESP), but are all
+functionally similar: they enable either the VPN client or the VPN server to
+transmit a signal to the peer, requesting an immediate reply which can be used
+to confirm that the link between the two peers is still working.
 .TP
 .B \-g,\-\-usergroup=GROUP
 Use