The Current connections item shows the window with current connections. This window contains information about the current TCP connections, or UDP and ICMP pseudoconnections, respectively, from particular stations in a local network.
The Current connections window contains a tree with two top-level items:
All computers — this option shows all computers which are in the Kerio Network Monitor database (see chapter 7.1).
Groups — particular groups (defined in the list of computers) are presented here.
The Current connections window shows only the computers (or groups, respectively) that have at least one connection open (the inactive computers are not displayed).
Computers included in a group are displayed under the group. Particular connections of a computer are displayed under each computer. The log for the concrete connection has the following structure:
TCP: zdenci:3568 -> 12.249.134.106:1214 290 + 183B 13 + 23B/s 3 / 2s Active *unknown*
TCP: — communication protocol (TCP, UDP or ICMP)
zdenci:3568 — name (or IP address) of a computer in a local network (typically a client) and the port number
12.249.134.106:1214 — name or IP address of a computer in the Internet (typically a server) and the destination port
290 + 183B — volume of the sent and received data (in bytes)
13 + 23B/s — speed of the transfer of the outgoing (sent) and incoming (received) data (in bytes per second)
2 + 3s — time of the last data transfer and total time the connection was open (in seconds)
Active — connection state (Syncing — connecting, Active — active / open, Closing by initiator — terminating by client, Closing by responder — terminating by server, Closed — terminated, !!! ERROR !!! — terminated because of an error).
Closed connections remain displayed in the Current connections window for time specified in the program configuration (see chapter 6.5).
An error occurs when a packet from a connection is lost and the connection lost synchronization (consecutively, the connection is terminated and the new one is established, if needed).
*unknown* — name of service (if it is defined in Kerio Network Monitor — e.g. SMTP, HTTP, FTP etc.) or *unknown* (unknown service)
Note: Kerio Network Monitor resolves names of computers using an analysis of the DNS procotocol. This can be done only if the DNS query was sent before the connection was initiated. If the client has this information in its local DNS cache, the DNS query is not sent and Kerio Network Monitor “sees” only the IP address of a destination server.
The Current connections toolbar contains the following functions and options (from left to right):
- Select columns & setup sorting
This button opens the dialog window for the Current connections window parameters settings.
- Columns included in the connection list
The user can select which columns (information) will be displayed in the Current connections window.
Connection type — type of connection (TCP connection, UDP or ICMP pseudoconnection)
Local address — name or IP address of a local (source) computer and a source port
Destination — name or IP address of a remote (target) computer and a target port
Three functions mentioned above show basic information about the connection and that's why it is not possible to turn them off (hide them).
Sent & received bytes count — number of sent and received bytes
Speed of the connection — speed of data transfer (incoming and outgoing direction)
Time of last data transfer / connection duration — time of the last data transfer and the total time of connection
Connection state — active, closed etc.
Connection info — information about the service (if it is defined in the program)
- Included protocols
Which protocols shall be monitored in the current connections window. Default settings include the TCP and UDP protocols.
- Sort the list on
Choice of an item that will be used for sorting of the output in the window (Destination address — destination IP address, Bytes transferred — volume of transferred data, Current speed — speed of the connection, Connection age — connection duration, Connection state — state of the connection).
- Refresh now
Updates information in the Current connections window.
- Refresh periodically
When this option is turned on, the information in the Current connections window will be refreshed automatically in the periodic time intervals (every 1 second).