From 28a64a848f378369f4f1cf30775d4eec444771ca Mon Sep 17 00:00:00 2001
From: Slava Bacherikov <slava@bacher09.org>
Date: Sun, 11 Jan 2026 11:29:52 +0200
Subject: [PATCH] nping: add docs about --badsum for ICMP

---
 nping/docs/nping-man.xml   | 17 +++++++++++++++++
 nping/docs/nping-usage.txt |  1 +
 nping/docs/nping.1         |  7 +++++++
 3 files changed, 25 insertions(+)

diff --git a/nping/docs/nping-man.xml b/nping/docs/nping-man.xml
index 2f1d73c66..9aa0c4b9c 100644
--- a/nping/docs/nping-man.xml
+++ b/nping/docs/nping-man.xml
@@ -1049,6 +1049,23 @@ SENT (4.0330s) TCP 192.168.0.21 &gt; 3.3.3.3:139
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term>
+        <option>--badsum</option> (Invalid Checksum)
+        <indexterm significance="preferred"><primary><option>--badsum</option> (Nping option)</primary></indexterm>
+        </term>
+        <listitem>
+          <para>
+           Asks Nping to use an invalid ICMP checksum for the packets sent to
+           target hosts. Since virtually all host IP stacks properly drop these
+           packets, any responses received are likely coming from a firewall or
+           an IDS that didn't bother to verify the checksum. For more
+           details on this technique, see
+           <ulink url="https://nmap.org/p60-12.html"/>.
+        </para>
+        </listitem>
+      </varlistentry>
+
     </variablelist>
 
     <refsect2 id="nping-man-icmp-types">
diff --git a/nping/docs/nping-usage.txt b/nping/docs/nping-usage.txt
index 3e0cfca29..f621829c8 100644
--- a/nping/docs/nping-usage.txt
+++ b/nping/docs/nping-usage.txt
@@ -39,6 +39,7 @@ ICMP PROBE MODE:
   --icmp-orig-time  <timestamp>    : Set originate timestamp.
   --icmp-recv-time  <timestamp>    : Set receive timestamp.
   --icmp-trans-time <timestamp>    : Set transmit timestamp.
+  --badsum                         : Use a random invalid checksum.
 ARP/RARP PROBE MODE:
   --arp-type <type>                : Type: ARP, ARP-reply, RARP, RARP-reply.
   --arp-sender-mac <mac>           : Set sender MAC address.
diff --git a/nping/docs/nping.1 b/nping/docs/nping.1
index dbb75605b..31af3a817 100644
--- a/nping/docs/nping.1
+++ b/nping/docs/nping.1
@@ -131,6 +131,7 @@ ICMP PROBE MODE:
   \-\-icmp\-orig\-time  <timestamp>    : Set originate timestamp\&.
   \-\-icmp\-recv\-time  <timestamp>    : Set receive timestamp\&.
   \-\-icmp\-trans\-time <timestamp>    : Set transmit timestamp\&.
+  \-\-badsum                         : Use a random invalid checksum\&.
 ARP/RARP PROBE MODE:
   \-\-arp\-type <type>                : Type: ARP, ARP\-reply, RARP, RARP\-reply\&.
   \-\-arp\-sender\-mac <mac>           : Set sender MAC address\&.
@@ -678,6 +679,12 @@ This option sets the Transmit Timestamp in ICMP Timestamp messages\&. The Transm
 is as with
 \fB\-\-icmp\-orig\-time\fR\&.
 .RE
+.PP
+\fB\-\-badsum\fR (Invalid Checksum)
+.RS 4
+Asks Nping to use an invalid ICMP checksum for the packets sent to target hosts\&. Since virtually all host IP stacks properly drop these packets, any responses received are likely coming from a firewall or an IDS that didn\*(Aqt bother to verify the checksum\&. For more details on this technique, see
+\m[blue]\fB\%https://nmap.org/p60-12.html\fR\m[]\&.
+.RE
 .SS "ICMP Types"
 .PP
 These identifiers may be used as mnemonics for the ICMP type numbers given to the