diff --git a/docs/FAQ.xml b/docs/FAQ.xml
index c94954f38..c37ed4948 100644
--- a/docs/FAQ.xml
+++ b/docs/FAQ.xml
@@ -1344,22 +1344,28 @@ DROP net fw udp 10619
Nov 25 18:58:52 linux kernel:
Shorewall:net2all:DROP:IN=eth1 OUT=
MAC=00:60:1d:f0:a6:f9:00:60:1d:f6:35:50:08:00 SRC=206.124.146.179
- DST=192.0.2.3 LEN=56 TOS=0x00 PREC=0x00 TTL=110 ID=18558 PROTO=ICMP
- TYPE=3 CODE=3 [SRC=192.0.2.3 DST=172.16.1.10 LEN=128 TOS=0x00 PREC=0x00
+ DST=192.0.2.3 LEN=56 TOS=0x00 PREC=0x00 TTL=110 ID=18558 PROTO=ICMP
+ TYPE=3 CODE=3 [SRC=192.0.2.3 DST=172.16.1.10 LEN=128 TOS=0x00 PREC=0x00
TTL=47 ID=0 DF PROTO=UDP SPT=53 DPT=2857 LEN=108 ]192.0.2.3 is external on my firewall... 172.16.0.0/24 is my
internal LAN
- Answer: While most people
- associate the Internet Control Message Protocol (ICMP) with
- ping, ICMP is a key piece of IP. ICMP is used to report
- problems back to the sender of a packet; this is what is happening here.
- Unfortunately, where NAT is involved (including SNAT, DNAT and
- Masquerade), there are a lot of broken implementations. That is what you
- are seeing with these messages. When Netfilter displays these messages,
- the part before the "[" describes the ICMP packet and the part between
- the "[" and "]" describes the packet for which the ICMP is a
+ Answer: First of all, please note
+ that the above is a very specific type of log message dealing with ICMP
+ port unreachable packets. Do not read this answer and assume that all
+ Shorewall log messages have something to do with ICMP (hint -- see FAQ 17).
+
+ While most people associate the Internet Control Message Protocol
+ (ICMP) with ping, ICMP is a key piece of IP. ICMP is used
+ to report problems back to the sender of a packet; this is what is
+ happening here. Unfortunately, where NAT is involved (including SNAT,
+ DNAT and Masquerade), there are a lot of broken implementations. That is
+ what you are seeing with these messages. When Netfilter displays these
+ messages, the part before the "[" describes the ICMP packet and the part
+ between the "[" and "]" describes the packet for which the ICMP is a
response.Here is my interpretation of what is happening -- to confirm this