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Communications Access Methods for SAS/CONNECT and SAS/SHARE Software

SAS/CONNECT

Local Host Tasks

User or Applications Programmer
To connect a UNIX local host with a remote host, perform these tasks at the local host:
  1. Consider the requirements of the remote host that you are connecting to.

  2. If you connect to a UNIX, an OS/390, or an OpenVMS Alpha remote host by means of the spawner program, then configure the spawner in the SERVICES file, as necessary.

  3. If you connect to a remote host by means of a spawner program, then set security, as necessary.

  4. Configure the local and the remote hosts' names and Internet addresses in the local HOSTS file or through the domain server.

  5. Specify the communications access method.

  6. Specify the remote node name.

  7. Specify a sign-on script, as necessary.

  8. Sign on to the remote host.

Remote Host Connection Considerations

If you are connecting to a Windows 95, Windows 98, or Windows NT remote host, you must connect by means of a spawner program that is already running on the remote host. If you are connecting to an OS/2, a UNIX, an OS/390, or an OpenVMS Alpha or VAX remote host, you may connect by means of a spawner program that also is already running on the remote host. A spawner program allows the encryption of userids and passwords when passed through the network. Without a spawner, readable userids and passwords are passed through the network, which may present a security risk. See Spawner Programs for information about starting the spawner on the remote host.

You may also sign on to the remote host with a script file. If you do not sign on with a script file, as a security measure, set the USER= and PASSWORD= options to the SIGNON statement, which is passed to the remote host, allowing a local host connection.

If the -NOSCRIPT option is set at the spawner invocation, sign on with a script is prohibited. Ask your network administrator whether the -NOSCRIPT option is set at the spawner invocation.

For all other hosts, you will sign on with a script.

Configuring the Spawner Service in the SERVICES File

To prepare for local hosts that connect to a UNIX, an OS/390, or an OpenVMS Alpha remote host with the spawner program, configure the spawner service in the SERVICES file at the local host. See Configuring the SERVICES File for more information.

Setting Security for Local Hosts

If you are not using a script file to sign on to the remote host, set security at the local host using either of the methods explained in Setting Security for SAS/CONNECT and SAS/SHARE. For Version 8 security behavior, specify the USER= and PASSWORD= options in the SIGNON statement. For details, see Providing Client Identification in a Version 8 Session.

For Version 7 security behavior, if you set the TCPSEC variable at the local host, either specify a userid and a password that are valid on the remote host or specify _PROMPT_ to supply the userid and password when connecting to a remote host. For information about setting the TCPSEC variable, see Providing Client Identification in a pre-Version 8 Session.

Configuring Local and Remote Host Names and Internet Addresses

You must specify the names and Internet addresses of the local and the remote hosts in the /etc/hosts file or through the name server. A server program supplies name-to-address translation, mapping from domain names to IP addresses. The server processor often runs on a dedicated processor, and the host itself is referred to as the name server.

The format for an /etc/hosts file entry follows: 

Internet-address host-name optional-alias

Example: 

172.20.10.200       monarch       local
172.20.10.201       omega         remote

Specifying the TCP/IP Communications Access Method

Note:   TCP/IP is the default communications access method on the UNIX platforms. You may omit specifying the access method in a COMAMID statement and the TCP/IP access method is assumed, by default.  [cautionend]

If you specify the TCP/IP communications access method to make a remote host connection, use the following syntax: 

OPTIONS COMAMID=access-method-id;

where COMAMID is an acronym for Communications Access Method Identification. access-method-id identifies the method used by the local host to communicate with the remote host. TCP (short for TCP/IP, which is an abbreviation for Transmission Control Protocol/Internet Protocol) is an example of an access-method-id.

Example: 

options comamid=tcp;

Alternatively, you may set this option at a SAS invocation or in a SAS configuration file.

Specifying the Remote Node Name

To make a connection from a UNIX local host to a remote host, use the following syntax: 

OPTIONS REMOTE=node-name[.service-name];

The value that is specified for node-name is based on the type of remote host that you are connecting to.

The value of the REMOTE= option must be a valid SAS name. See SAS Language Reference: Dictionary for details about SAS naming rules.

Example: 

options remote=rmthost;

If you use an Internet address (or some other invalid SAS name), you must assign the address to a macro variable and specify the macro variable for the value of the REMOTE= option, illustrated as follows: 

%let mynode=Internet-address;
options remote=mynode;

Do not choose a macro name that is also a valid host name on your network. SAS first attempts to reach a network host with the value of the REMOTE= option (in this example, MYNODE).

Example: 

%let rmtnode=172.20.10.200;
options remote=rmtnode;

Identifying a Script File for Signing On and Signing Off

To use one of the sample script files that is supplied with SAS/CONNECT for signing on and signing off, assign the RLINK fileref to the appropriate script file, based on the remote host that you are connecting to. The sample scripts are installed at !sasroot /misc/connect. You must customize the sample scripts to accurately reflect your site logon procedures. Failure to do so will produce errors.

The FILEREF syntax follows: 

FILENAME RLINK '!sasroot/misc/connect/script-name';

where script-name specifies the appropriate script file for the remote host.

The following table lists the scripts that are supplied by SAS Institute:

UNIX TCP/IP SAS/CONNECT Sign-on Scripts
Remote Host Script Name
CMS tcpcms.scr
CMS (using full-screen 3270 TELNET protocol) tcpcms32.scr
TSO under OS/390 tcptso.scr
OS/390 (without TSO) tcpmvs.scr
OS/390 (using full-screen 3270 TELNET protocol) tcptso32.scr
OpenVMS tcpvms.scr
OS/2 tcpos2.scr
UNIX tcpunix.scr
Windows NT, Windows 95 , and Windows 98 tcpwin.scr

Example: 

filename rlink '!sasroot/connect/saslink/tcptso.scr';

Note:   If you connect to a PC or UNIX spawner program, then you may optionally sign on with a script file unless the spawner is invoked with the -NOSCRIPT option. In this case, you cannot use a script file. With no script file, you do not define an RLINK fileref statement. See Spawner Programs for more information.  [cautionend]

Note:   If you connect to an OS/2 remote host by means of a TELNET daemon, then your script must invoke the SASDMR program in the TYPE statement that starts the remote SAS session.  [cautionend]

Signing On to the Remote Host

To complete your sign on to the remote host, enter the SIGNON statement, as follows: 

signon user=_prompt_;

To set security at the remote host, specify valid values for the USER= and PASSWORD= options in the SIGNON statement. For details, see Providing Client Identification in a Version 8 Session.

If the NOSCRIPT option was set when the UNIX spawner program was invoked, then you cannot use a script file. Ask the network administrator if sign ons with scripts are allowed. An example of signing on without a script follows: 

signon noscript;

Local Host Example

The following example illustrates the statements that you specify in a UNIX local host SAS session to connect to a remote host with the TCP/IP access method: 

filename rlink '!sasroot/misc/connect/tcptso.scr';
options comamid=tcp remote=rmtnode;
signon;

The first line identifies the script file that you use to sign on to an OS/390 remote host. The script file contains a prompt for a userid and a password that are valid on the remote host. The TCP/IP communications access method is declared with a connection to the remote host RMTNODE.

Remote Host Tasks

System Administrator
Before a user on a local host can sign on to a UNIX remote host by means of a UNIX spawner program, perform the following tasks:
  1. If you connect to the UNIX spawner program, configure the UNIX spawner service in the
    /etc/services file at the remote host.

  2. Start the UNIX spawner program at the remote host, as necessary.

Configuring the UNIX Spawner Service in the SERVICES File

To prepare a local host to connect to a UNIX remote host by means of the UNIX spawner program, configure the spawner service in the /etc/services file on the remote host. See Configuring the SERVICES File for more information

Starting the UNIX Spawner Program at the Remote Host

Note:   Running the UNIX spawner program on a UNIX remote host is optional.  [cautionend]

You optionally invoke the UNIX spawner program on the UNIX remote host to enable local hosts to connect to it. The spawner program resides on a remote host and listens for SAS/CONNECT client requests for connection to the remote host. After the spawner program receives a request, it invokes the remote SAS session. See UNIX Spawner Program for information about starting the UNIX spawner program.

Note:   If you set the -NOSCRIPT option at the UNIX spawner invocation, inform local users that they cannot sign on with a script file.  [cautionend]

If you connect to a UNIX spawner without a script file, you must invoke the spawner with the -SASCMD option and an executable file on the remote host. The executable file starts the remote SAS session.

Remote Host Example

You may set the following variables in the remote host configuration file to restrict port access: 

options tcpportfirst=5020;
options tcpportlast=5050;

These statements restrict access to ports 5020 through 5050.

A typical example of how to invoke the UNIX spawner program at the UNIX remote host follows: 

!sasroot/utilities/bin/sastcpd -service unxspawn

The UNIX spawner program UNXSPAWN is invoked.


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Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.