TMeter :: Monitoring

Host Monitoring

Feature "Host Monitoring" allows tracking a host state ("up/down"). You can define an unlimited number of IP-adress ranges which will be pinged (by sending and recieving ICMP packets) periodically and consequentially. The result of host polling (for the current ping serial) will be host state with the following:

State 'OK' defines that ICMP replies were received successfully for all ICMP requests.
State 'Offline' says that ICMP replies were not received for ICMP requests.
State 'QualityDrop' defines that at least one ICMP request was received for several ICMP requests.

To receive ICMP packets for Host Monitoring purposes, you should enable the traffic capturing on the corresponding network adapter (or select several network adapters).

An algorithm of Host Monitoring

The single step (iteration) of Host Monitoring is called as "ping serial". For every IP address range defined for Host Monitoring, you can define unique quantity of ping attempts in ping serial. When ping serial is finished, new state will be assigned for every host in the range. Next (after defined time interval), the ping serial will be repeated. IP addresses are pinged from the first to the last IP address consequentially in the range with defined time interval (by default, 20 milliseconds - this value can be changed via registry settings DelayBetweenPing).

Notes about Host Monitoring in LAN

In LAN (assume, that LAN consists of single Ethernet segment), it is possibly to track MAC addresses of hosts. Therefore, if you even have dynamic IP address assignment, it will be no problem to identify host state history in case of changing IP address. Moreover, if host is up but doesn't respond on ICMP requests, the corresponding MAC address record will be created anyway:

When MAC-address is appeared without changing host state, new monitoring event will be created with "+mac" marker
When MAC-address is disappeared without changing host state, new monitoring event will be created with "-mac" marker

For every captured MAC address, it is possible to display a name of hardware vendor, which "owns" that MAC address. The hardware vendor is looking for in OUI base (Organizationally unique identifier).

Displaying monitoring results on external resource

If you want watch Host Monitoring without using TMeter Administrative Console, you can visit built-in TMeter webserver http://localhost:7643/traffic/hostmonitoring.xml

Recording monitoring events into database

You can enable recording monitoring events into database. Database connection string is common for the filterset and you can define it on the corrensponding tab in TMeter Administrtive Console. Before recording, you should create database table with the following fields:

N	Field name	Field type	Description
1.	id	int	Id of record, primary key (int with autoincrement)
2.	Dt	Datetime	Time of record insertion. This field should be filled automatically by SQL Server.
3.	RangeId	int	Id of IP address range
4.	StatusId	int	Host status Id (1 - 'OK', 2 - 'Offline', 3 - 'QualityDrop')
5.	Ip	varchar(20)	Host IP address in decimal dot notation
6.	Hostname	varchar(100)	Hostname (found in reverse DNS zone)
7.	Descr	varchar(260)	Host description based on IP- or MAC- address equality
8.	MacAddr	varchar(20)	MAC address
9.	MacVendor	varchar(260)	Hardware vendor found in OUI base by MAC-address
10.	TypeId	int	Event type (0 - changing status, 1 - appearing MAC-address without changing status, 2 - disappearing MAC-address without changing status)

Script for creating database table for Microsoft SQL Server

CREATE TABLE [dbo].[Monitoring](
        id int IDENTITY NOT NULL PRIMARY KEY,
        Dt datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
        RangeId int NOT NULL,
        StatusId int NOT NULL,
        Ip varchar(20) NOT NULL,
        Hostname varchar(100) NULL,
        Descr varchar(260) NULL,
        MacAddr varchar(20) NULL,
        MacVendor varchar(260) NULL,
        TypeId int NULL
)

Note

Actual time interval between ping serials can be different from specified in TMeter Adminstrative Console and depends on total number of hosts included in Host Monitoring.