X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/51113adb98c4d82ab799ab38ea463427d0780daa..844abf94571ffdd3e113c518947073ff5375d748:/svc/connect.8.in

diff --git a/svc/connect.8.in b/svc/connect.8.in
index 7021c6b6..468a5c6d 100644
--- a/svc/connect.8.in
+++ b/svc/connect.8.in
@@ -27,7 +27,7 @@
 .so ../defs.man.in \"@@@PRE@@@
 .
 .\"--------------------------------------------------------------------------
-.TH connect 8 "11 December 2007" "Straylight/Edgeware" "TrIPE: Trivial IP Encryption"
+.TH connect 8tripe "11 December 2007" "Straylight/Edgeware" "TrIPE: Trivial IP Encryption"
 .
 .\"--------------------------------------------------------------------------
 .SH "NAME"
@@ -370,7 +370,30 @@ The parameters are as follows.
 .TP
 .B every
 A time interval: how often to ping the peer to ensure that it's still
-alive.  The default is 2 minutes.
+alive.  The default is 30 seconds for active dynamic peers, and 5
+minutes for passive peers.
+.IP
+The period for dynamic peers should be no longer than
+.I timeout
+\(mu
+.RI ( retries
+\- 1).  Consider an idle mobile peer which has its IP address changed
+just before its passive peer begins pinging.  The static peer's pings
+will go to the old address until it receives a ping back from the mobile
+peer.  Therefore, the static peer has to keep pinging until it would
+definitely have received an unsolicited ping from the mobile peer, and
+therefore be informed of the change of address.  And it's no use
+learning about the change of address just after sending the last ping to
+the old address, so the last retry doesn't count for the purposes of
+this calculation.
+.IP
+Besides, the consequences of failed pinging differ between dynamic and
+passive peers.  In the former case, a failure provokes a reconnection
+attempt, after which (hopefully) things will work again: it's probably a
+good thing to check frequently and fail fast.  In the latter case, the
+dynamic peer will certainly have to notice that it's been abandoned and
+arrange to retry, causing a communication failure where maybe there
+wasn't really one before.
 .TP
 .B timeout
 A time interval: how long to wait for a reply before retrying or giving