[IPV4]: Update icmp sysctl docs and disable broadcast ECHO/TIMESTAMP by default

It's not a good idea to be smurf'able by default.
The few people who need this can turn it on.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index ab65714d95fc..b433c8a27e2d 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -355,10 +355,14 @@ ip_dynaddr - BOOLEAN
         Default: 0
 
 icmp_echo_ignore_all - BOOLEAN
+        If set non-zero, then the kernel will ignore all ICMP ECHO
+        requests sent to it.
+        Default: 0
+
 icmp_echo_ignore_broadcasts - BOOLEAN
-        If either is set to true, then the kernel will ignore either all
-        ICMP ECHO requests sent to it or just those to broadcast/multicast
-        addresses, respectively.
+        If set non-zero, then the kernel will ignore all ICMP ECHO and
+        TIMESTAMP requests sent to it via broadcast/multicast.
+        Default: 1
 
 icmp_ratelimit - INTEGER
         Limit the maximal rates for sending ICMP packets whose type matches