Updated Readme file with the TCP ping feature

diff --git a/Readme b/Readme
index f30d808..607319f 100644 (file)
--- a/Readme
+++ b/Readme
@@ -15,8 +15,8 @@ through pings to them.
 
 1.1. Rationale
 ---------------------------------------
-The application uses ICMP echo requests messages to verify if a given host
-is available or not.
+The application uses ICMP echo requests messages, or TCP segments to verify
+whether a given host is available (up) or not (down).
 
 The host's address can be an IP or a DNS.
 
@@ -46,7 +46,7 @@ about this in the beginning of the source code.
 
 2.   Configuration file
 =======================================
-In this section are describled the configuration items, along with they
+In this section are described the configuration items, along with they
 possible values and meanings. This section is organized in each major
 configuration block.
 
@@ -60,6 +60,7 @@ This configurations are shared among and affect all the hosts.
   lookup server which the application will query first. If left blank or omited,
   it will use the /etc/resolv.conf.
   You can use the nslookup <host> to figure out the nameserver.
+- ping-protocol: select one of the available ping protocols (ICMP or TCP).
 - hosts-down-limit: an absolute number, which ranges from 0 to the number of
   hosts available. This value represents the minimum number of hosts that have
   to fail (i.e. do not reply to the ping) in order to alert any external system.
@@ -80,6 +81,8 @@ This configurations are shared among and affect all the hosts.
 - name: the DNS or IP of the host to ping. Take in consideration that, if a
   DNS is given, the application pings all IPs in the look up table, however, if
   IP is provide, it is the only which will be pinged.
+- port: when using a port based protocol, like TCP, this field specifies in
+  which port to ping the host.
 - interval: the host will be pinged every "interval" seconds.
 
 
@@ -100,3 +103,4 @@ following:
 [3]  http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
 [4]  http://www.boost.org/doc/libs/1_45_0/doc/html/boost_asio.html
 [5]  http://www.boost.org/doc/libs/1_45_0/doc/html/program_options.html
+[6]  http://www.networkuptime.com/nmap/page4-4.shtml