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:
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:
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|
|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 )
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.