![CommBufferSize connection parameter [CBSIZE]](gif/backward.gif)
![Compress connection parameter [COMP]](gif/forward.gif)
ASA Database Administration Guide
Connection and Communication Parameters
Connection parameters
To specify client side network communications protocols.
Anywhere. The CommLinks (LINKS) connection parameter is optional for connections to a personal server, and required for connections to a network server.
String
Use only the shared memory communications protocol to connect.
If you do not specify a CommLinks (LINKS) connection parameter, the client searches for a server on the current machine only, and only using a shared memory connection. This is the default behavior, and is equivalent to CommLinks=ShMem. The shared memory protocol is the fastest communication link between a client and server running on the same machine, as is typical for applications connecting to a personal database server.
If you specify CommLinks=ALL, the client searches for a server using all available communication protocols. Since there may be an impact on performance if you specify CommLinks=ALL, use this setting only when you don't know which protocol to use.
If you specify one or more protocols in the CommLinks (LINKS) connection parameter, the client uses the named communication protocol(s), in the order specified, to search for a network database server. A connection error appears and the connection attempt aborts if the connection fails to connect using a specified protocol, even if there are protocols remaining in the list to try.
CommLinks (LINKS) connection parameter values are case insensitive, and include:
SharedMemory (ShMem) Start the shared memory protocol for same-machine communication. This is the default setting. The client tries shared memory first if it appears in a list of protocols, regardless of the order in which protocols appear.
ALL Attempt to connect using the shared memory protocol first, followed by all remaining and available communications protocols. Use this setting if you are unsure of which communication protocol(s) to use.
NamedPipes (NP) For C2 security purposes, connect from a Windows NT/2000/XP client to a database server on the same machine that was started with the -sc option.
TCPIP (TCP) Start the TCP/IP communications protocol. TCP/IP is supported on all operating systems.
SPX Start the SPX communications protocol. The SPX protocol is supported for Windows and NetWare clients.
Each of these values can have additional network communications parameters supplied.
For a list of parameters, see Network communications parameters.
You may wish to use a specific protocol, as opposed to ALL, for the following reasons:
The network library starts slightly faster if the client uses only necessary network protocols.
Connecting to the database may be faster.
You must specify the protocol explicitly if you wish to tune the broadcast behavior of a particular protocol by providing additional network communications parameters.
The CommLinks (LINKS) connection parameter corresponds to the database server -x option.
The following connection string fragment starts the TCP/IP protocol only:
CommLinks=tcpip
The following connection string fragment starts the shared memory protocol and searches for the database server over shared memory. If the search fails, it then starts the TCP/IP port and searches for the server on the local network. If that fails, it starts the SPX port and searches for the engine over SPX.
CommLinks=tcpip,shmem,spx
The following connection string fragment starts the SPX port and searches for the engine over SPX. If the search fails, it then starts the TCP port and searches for the server on the local network, as well as the host kangaroo. Note that if the server is found over SPX, the TCP port is NOT started.
CommLinks=spx,tcpip(HOST=kangaroo)
Network communications parameters