snmp custom data, fix few typos (#190)

* small update

* first version

* add custom data

* update tcp ping closed

Author: xmacan

Devices.md

@@ -57,7 +57,8 @@ They include:
 - **SNMP Uptime** - Query the SNMP Uptime Instance OID
 - **Ping and SNMP Uptime** - Ping the device but also check the SNMP Uptime
   Instance OID
-- **Ping** - Either ICMP, TCP at a port, or UDP as a port
+- **Ping** - Either ICMP, TCP at a port, or UDP as a port. Newer version has an aditional method TCP Ping Closed. 
+The device is considered UP even if the tcp ping returns closed 
 - **Ping or SNMP Uptime** - Only one needs to be working for Cacti to collect data
 - **SNMP Desc** - Query the SNMP sysDescription in cases where the SNMP Uptime OID
   is not available

How-To-SNMP-Custom-Script.md

@@ -0,0 +1,46 @@
+# How To Extend snmpd with custom script/data
+
+Some SNMP servers can be extended with custom scripts or programs. The output of the running script can then 
+be read using the OID and can therefore be easily used in Cacti. An example is the thermometer on the USB port.
+In combination with [Graph a Single SNMP OID](Graph-a-Single-SNMP-OID.md), this is a very simple way to display such data
+
+We will show the procedure for the very extensive Net-SNMP and FreeBSD BSNMPD.
+
+## Linux Net-SNMP
+  Simply add a line to /etc/snmpd.conf and restart snmpd
+  **> extend test /bin/echo hello**
+
+  Result will be here:
+  **> snmpwalk -v2c -c testing 127.0.0.1 nsExtendOutput1**
+  ``
+  NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."test" = STRING: hello
+  NET-SNMP-EXTEND-MIB::nsExtendOutputFull."test" = STRING: hello
+  NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."test" = INTEGER: 1
+  NET-SNMP-EXTEND-MIB::nsExtendResult."test" = INTEGER: 0``
+
+  For Cacti you need numeric OID, you can use snmptranslate:
+  **> snmptranslate -On NET-SNMP-EXTEND-MIB::nsExtendOutput1Line.\"test\"**
+
+  The result is an OID that we can use:
+  ``.1.3.6.1.4.1.8072.1.3.2.3.1.1.4.116.101.115.116``
+
+
+## FreeBSD BNSMPD
+  You need install bsnmp-ucd
+  **> pkg install bsnmp-ucd**
+
+  Add these lines to /etc/snmpd.config and restart bsnmpd
+  begemotSnmpdModulePath."ucd" = "/usr/local/lib/snmp_ucd.so"
+  %ucd
+  extNames.0 = "first command"
+  extCommand.0 = "/path/to/script.sh"
+  extNames.1 = "second command"
+  extCommand.1 = "/path/to/script.sh param1"
+
+  Name and result of first command have the same intex:
+  **> snmpwalk -v2c -c testing 127.0.0.1 .1.3.6.1.4.1.2021.8.1.2.0**
+  ``.1.3.6.1.4.1.2021.8.1.2.0 = STRING: first command``
+
+  **> snmpwalk -v2c -c testing 127.0.0.1 .1.3.6.1.4.1.2021.8.1.101.0**
+  ``.1.3.6.1.4.1.2021.8.1.101.0 = STRING: 15``
+

How-To-Setup-Remote-Pollers.md

@@ -2,15 +2,19 @@
 
 Remote Pollers add complexity to your cacti setup while also massively extended
 the scalability of it.  Remote Pollers allow system admins to distribute
-the load of polling between different servers as well as provideanother source
-of polling close to a device
+the load of polling between different servers as well as provide another source
+of polling close to a device.
 
-For example you may have a device in toronto but if your pollers are in Newyork
+For example you may have a device in Toronto but if your pollers are in New York
 the network latency may causes issues with your metrics having a remote poller
-in Toronto in this case will help with that issue
+in Toronto in this case will help with that issue.
 
 ## Setup Instructions
 
+The process of remote poller installation is similar to cacti installation.
+In the wizard, select the installation type for Remote poller. For the remote poller
+you must use the same version of cacti as the main poller installation.
+
 With this setup the following layout is assumed
 
 - Main server IP is 192.168.1.5

Plugins.md

@@ -1,10 +1,14 @@
 # Plugin Management
 
+Installing or updating plugins on cacti is a simple procedure.
+For most of the plugins a few basic steps are enough, which are described below.
+Each plugin directory should contain a README.md file. We recommend to study
+this file. It may contain important installation information.
+
 ## Installing Plugins
 
 ![plugins](images/plugins.png)
 
-Installing plugins on cacti is a simple procedure
 
 1. Download the plugin to cactidir/cacti/plugins
 

README.md

@@ -334,13 +334,15 @@ PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
 9. [How To Setup SSH Tunnels](How-To-SSH-Tunnels.md)
 
-10.[Enable SSL for Cacti](Cacti-SSL-Configuration.md)
+10. [Enable SSL for Cacti](Cacti-SSL-Configuration.md)
 
-11.[Graph a Single SNMP OID](Graph-a-Single-SNMP-OID.md)
+11. [Graph a Single SNMP OID](Graph-a-Single-SNMP-OID.md)
 
-12.[Change poller interval from 5 minutes to 1 minute ](How-To-Poller-5-to-1-min.md)
+12. [How To Extend snmpd with custom script/data](How-To-SNMP-Custom-Script.md)
 
-13.[Convert from Package based install to source on Ubuntu/Debian](convert-from-package-to-source-debian-ubuntu.md)
+13. [Change poller interval from 5 minutes to 1 minute ](How-To-Poller-5-to-1-min.md)
+
+14. [Convert from Package based install to source on Ubuntu/Debian](convert-from-package-to-source-debian-ubuntu.md)
 
 ### Video Tutorials