Default network monitoring settings
This section of the program's settings configures
the default settings for background monitoring, which returns device status (active, inactive) in real-time. When a new device is added on the map, these default checks are assigned to it (you can assign other checks later). The program uses the following two default methods for checking whether hosts are available:
- Sending ICMP echo packets (regular ping)
- Connecting to specified TCP port (for instance, FTP)
It can use these both methods simultaneously. In this case, the device will be first pinged with the ICMP ping and then,
when no positive result has been received the program will attempt to connect to the specified TCP port.
ICMP ping parameters:
- Response timeout (in milliseconds) - length of time, within which the program expects response from each device.
- Number of packets – if the number of packets is greater than one, if the negative response is received for the first packet, the remaining packets will be still sent to the remote host. This eliminates the possibility of false detection of object status when a single packet is lost.
- Packet size – size of ICMP packets, in bytes.
You can change ICMP ping settings for all devices on map by clicking the button "Apply to all devices".
TCP port parameters:
- TCP port (for example, 21 for FTP, 80 for HTTP, etc.).
- Response timeout (in milliseconds) - length of time, within which the program expects response from each device.
You can change TCP port settings for all devices on map by clicking the button "Apply to all devices".
Since most hosts in modern networks are protected with firewalls, pinging those hosts regularly may not work out (if ICMP echo replies are disabled). In such cases, checking by opening a TCP connection to a specific port of the host may help out. For example, it is common for local area networks to set up FTP services on users' computers. In this case, we can check availability of hosts by attempting to connect to their TCP port 21 (FTP) or port 139 (NetBios).