diff --git a/man7/ip.7 b/man7/ip.7
index d22ac7081..4e50ac2ca 100644
--- a/man7/ip.7
+++ b/man7/ip.7
@@ -9,7 +9,7 @@
 .\"
 .\" FIXME: Document IP_MINTTL, added in Linux 2.6.34
 .\"
-.TH IP  7 2010-10-24 "Linux" "Linux Programmer's Manual"
+.TH IP  7 2011-09-22 "Linux" "Linux Programmer's Manual"
 .SH NAME
 ip \- Linux IPv4 protocol implementation
 .SH SYNOPSIS
@@ -310,22 +310,32 @@ Only valid as a
 .\" Precisely: 2.1.124
 Set or receive the Path MTU Discovery setting for a socket.
 When enabled, Linux will perform Path MTU Discovery
-as defined in RFC\ 1191
-on this socket.
-The don't-fragment flag is set on all outgoing datagrams.
-The system-wide default is controlled by the
-.I /proc/sys/net/ipv4/ip_no_pmtu_disc
-file for
+as defined in RFC\ 1191 on
 .B SOCK_STREAM
-sockets, and disabled on all others.
+sockets.
 For
 .RB non- SOCK_STREAM
-sockets, it is the user's responsibility to packetize the data
-in MTU sized chunks and to do the retransmits if necessary.
-The kernel will reject packets that are bigger than the known
-path MTU if this flag is set (with
-.B EMSGSIZE
-).
+sockets,
+.B IP_PMTUDISC_DO
+forces the don't-fragment flag to be set on all outgoing packets.
+The don't-fragment flag is set on all outgoing datagrams.
+It is the user's responsibility to packetize the data
+in MTU-sized chunks and to do the retransmits if necessary.
+The kernel will reject (with
+.BR EMSGSIZE )
+datagrams that are bigger than the known path MTU.
+.B IP_PMTUDISC_WANT
+will fragment a datagram if needed according to the path MTU,
+or will set the don't-fragment flag otherwise.
+
+The system-wide default can be toggled between
+.B IP_PMTUDISC_WANT
+and
+.B IP_PMTUDISC_DONT
+by writing (respectively, zero and nonzero values) to the
+.I /proc/sys/net/ipv4/ip_no_pmtu_disc
+file.
+
 .TS
 tab(:);
 c l