- What is a port?
- HFSQL Client/Server: Ports used
- HFSQL server
- Registering the ports used by HFSQL Client/Server to IANA
- Use via Internet
- How do I specify the port in the client application?
- Why are some ports closed by default?
HFSQL Client/Server: Managing the ports
Available only with this kind of connection
A port is an entry point to a service (web service, dns service, email service, HFSQL server) on an hardware device (pc, server) connected to a network.
On a network (TCP-IP) each equipment owns at least one IP address. Each address support no less than 65000 ports offering a service.
The services are referenced and they are used to assign the ports.
- A Web site is available on port 80
- Sending emails is performed on port 25 and receiving emails on port 110,
- A HFSQL server is accessible by default on port 4900 and MantaManager on port 4999.
In other words: applications are running on a server. To dialog with these applications, a "pipe" identified by a number is required: the port number.
Examples: a Web server uses port 80. Telnet port 23. HFSQL server: 4900 (by default).
HFSQL Client/Server: Ports used
The HFSQL server uses port 4900 by default (TCP port).
This port can be configured via the HFConf.ini
file found in the setup directory of the HFSQL server.
MantaManager uses a fixed port 4999 (5002 by compatibility). This service is not required to access an HFSQL server: it is used to list the servers found on a computer and to start a server on the computer.
Therefore, there is no need to open this port on Internet.
Remark: It is possible to choose another port provided that the port is valid:
- less than 65535,
- greater than 1024 (otherwise, special privileges are required),
- not being used by another process.
Registering the ports used by HFSQL Client/Server to IANA
The port numbers used by HFSQL Client/Server are now assigned by IANA (Internet Assigned Numbers Authority).
These port numbers are as follows:
- 4900: HFSQL Client/Server engine (TCP port)
- 4999: administration of the HFSQL Client/Server engines. The port 4999 is a TCP port for listing servers and starting servers, and a UDP port for detecting servers on a local area network (LAN).
Since IANA has assigned port 4999 to HFSQL Client/Server engine management, this service manages the official 4999 port by default and continues to support port 5002 for backward compatibility.
When HFSQL Client/Server is used via Internet, the name of the server must be specified in the connection of the client application. This name can be the name or the IP address of the server.
If your server can be identified by a name (for example: zeus.org), this name can be used in the connection. This name must be saved in a DNS service (that can be dynamic as dyndns, no-ip for example)
If the server has a fixed IP address, you can use it directly (126.96.36.199 format).
To access the server from the Internet, a port must be opened in the firewall that protects the server.
- Place the server in the DMZ, then all the server ports will be visible from Internet. If the server is protected by its own software Firewall (the one of SP2 of Windows XP, IpTable in Linux for instance), the port of the HFSQL server must be opened (4900 by default).
- Perform a port forward to its firewall-router.
- A rule must be added to the router. This rule specifies that the connections coming on port X from Internet will be transferred to the computer that hosts the HFSQL server on 4900 (or on the port specified in HFConf.ini)
- The port X visible from Internet must be used for the client.
If the client uses a firewall, this one must allow the applications to connect via the port used toward the outside
How do I specify the port in the client application?
To specify the port in the client application:
- Solution 1: Specify the port in the analysis ("Advanced" tab in the connection description).
- Solution 2: Specify the port through programming: the name or the IP address of the server must be followed by: (colon) and by the port number (for example "zeus.org:4920" or "188.8.131.52:4920" ).
HOpenConnection("MyConnection", "user", "pwd", "zeus.org:4920", ...)
Why are some ports closed by default?
The security is improved by limiting the number of ports opened on the computer: software failure of the OS, service not configured properly, unprotected service.
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