Database Administrator's Guide

COMM_PROTOCOL F_TCPIP

COMM_PROTOCOL F_TCPIPV6 (using an IPv6 socket)

COMM_PROTOCOL FSHAREMM

COMM_PROTOCOL DISABLE

Specifies a communications module loaded by the server. See FairCom Server Installation for the communications options available for your platform.

If COMM_PROTOCOL is not specified, the default protocol is used.

The default protocol is disabled when the COMM_PROTOCOL keyword is used. If the default protocol is required in addition to other protocols, use the technique described below to specify multiple protocols.

Note: The COMM_PROTOCOL option specifies the protocol used for ISAM connections. By default, local SQL connections use shared memory unless the SQL_OPTION NO_SHARED_MEMORY keyword is specified. See the c-treeSQL Server Operations and Utilities Guide for more information about the communication protocol for SQL connections.

V12: Default to IPv6 in Windows when TCP/IP is Selected

When the user selects TCP/IP, the FairCom build system now defaults to enabling IPv6 instead of only IPv4. This change makes this Internet protocol available by default to ensure your applications have support for the latest standards.

To begin using IPv6 support, you must enable the TCP/IP communication protocol support on the FairCom DB Server side by making sure this keyword is enabled in ctsrvr.cfg:

COMM_PROTOCOL F_TCPIPV6

It is possible to have both IPv4 and IPv6 support enabled at the same time.

IPv4 and IPv6

Native SQL clients on Windows will attempt to connect to the first address (IPv4 or IPv6) resolved for the host.

Note: In V11, IPv6 is supported on Windows and Linux. Java and ADO.NET SQL clients currently support only IPv4. Explicit IPv6 addresses in client connection strings are not currently supported.

Server keyword SQL_OPTION NO_IPV6 can be added to ctsrvr.cfg to accept only IPv4 connections. This is not generally recommended and is more likely to cause connection issues than to solve them.

An environment variable can be used for native clients to request only IPv4 address: CTSQL_IPV4_ONLY. Setting this variable to any value in the environment will effectively disable IPv6 connection attempts from the client. This may be needed on networks where both IPv4 and IPv6 are enabled, but the c-tree SQL server does not accept IPv6 connections.

Note: The COMM_PROTOCOL F_TCPIPV6 keyword is commented out in the default ctsrvr.cfg file. Be sure to remove the comment symbol (the semicolon - ;) before trying to use this support.

Default Protocol Override

An application can override the default protocol by specifying the protocol in the connection string with the following syntax:

FAIRCOMS@myhost^F_TCPIP

or

FAIRCOMS@myhost^F_TCPIPV6

Shared Memory

On Windows, FairCom Server can automatically detect and utilize shared memory when a TCP/IP client is in use. Include COMM_PROTOCOL FSHAREMM in the ctsrvr.cfg file for this to be triggered.

Multiple Protocols

FairCom Server on Windows, Linux, AIX, and Solaris (both SPARC and X86/X64) can support TCP/IP and shared memory simultaneously. For example, FairCom Server could be communicating with some users locally through shared memory and others using TCP/IP over an Ethernet connection.

Each protocol to be loaded by the FairCom Server requires a separate COMM_PROTOCOL line in the configuration script. The following example loads TCP/IP and Shared Memory Model protocols:

COMM_PROTOCOL F_TCPIP

COMM_PROTOCOL FSHAREMM

To support both IPv4 and IPv6 in the same FairCom DB Server, list the following keywords:

• COMM_PROTOCOL F_TCPIP
• COMM_PROTOCOL F_TCPIPV6

Note: If more than one protocol is to be used, a separate COMM_PROTOCOL entry must be specified for each protocol.

TCP/IP Encryption

Encryption of c-tree’s TCP/IP communication protocol allows an added level of security for client/server applications. FairCom DB supports TLS/SSL, as described in Transport Layer Security Secures Data in Transit between Network FairCom DB Clients and Servers.

Note: The FETCPIP protocol activates CAMO, which should be considered deprecated. CAMO or "Camouflage" is an older, legacy method of hiding data, which is not a standards-conforming encryption scheme, such as AES. It is not intended as a replacement for Advanced Encryption or other security systems.

Identifying the FairCom Server Host Machine

Every protocol makes assumptions about the location of the machine hosting the FairCom Server. Use the following table to determine the proper method for the client to find the FairCom Server based on the protocol selected. SERVER_NAME is the name specified by the SERVER_NAME keyword, FAIRCOMS by default.

HostName is the network ID for the host machine. It can also be an IP address with TCP/IP.

Disable Communications

COMM_PROTOCOL DISABLE inactivates all communications.

When this keyword is specified in the FairCom Server configuration file, the server’s communication subsystem is disabled at server startup, and remains disabled during the entire lifetime of the server process. This feature is useful when the FairCom Server is loaded as a DLL or shared library into an application server process. Although external clients are prevented from using the FairCom Server, threads in the application server process can use the FairCom Server subsystem. This option can also be used to prevent ISAM-level access to a FairCom DB SQL Server.

When this option is in effect, the server logs the following message to CTSTATUS.FCS:

FairCom DB Server communication subsystem is disabled.

Default: All servers load TCP/IP as the default.

See Also:

• Transport Layer Security Secures Data in Transit between Network FairCom DB Clients and Servers
• Shared Memory Resource Considerations
• Shared Memory Protocol Change