Sun Java System Portal Server Secure Remote Access 7.2 Administration Guide

Netlet Rule Examples

This section contains some examples of Netlet rules to illustrate how Netlet syntax works.

Basic Static Rule

This rule supports a Telnet connection from the client to the machine sesta.

Rule Name 

Encryption Cipher 

Remote Application URL 

Download Applet 

Extend Session 

Map Local Port to Destination Server Port 

myrule 

SSL_RSA_WITH_RC4_128_MD5

null 

Do not select the checkbox 

true 

  • Local Port: 1111

  • Destination Host: sesta

  • Destination Port: 23

where

myrule is the name of the rule.

SSL_RSA_WITH_RC4_128_MD5 indicates the cipher to be used.

null indicates that this application is not invoked by a URL or run through the desktop.

false indicates that the client does not download an applet to run this application.

true indicates that Portal Server should not time out when the Netlet connection is active.

1111 is the port on the client where Netlet listens for a connection request from the destination host.

sesta is the name of the recipient host in the Telnet connection.

23 is the port number on the destination host for the connection, in this case the well-known port for Telnet.

The desktop Netlet provider does not display a link, but Netlet automatically starts and listens on the port specified (1111). Instruct the user to start the client software - in this case a Telnet session that connects to localhost on port 1111.

For example, to start the Telnet session, the client needs to type the following on the UNIX command line in a terminal:


telnet localhost 1111

Static Rule With Multiple Host Connections

This rule supports a Telnet connection from the client to two machines, sesta and siroe.

Rule Name 

Encryption Cipher 

Remote Application URL 

Enable Download Applet 

Enable Extend Session 

Map Local Port to Destination Server Port 

myrule 

SSL_RSA_WITH_RC4_128_MD5

null 

Do select the checkbox 

Select the checkbox 

  • Local Port: 1111–1234

  • Destination Host: sesta-siroe

  • Destination Port: 23

where

23 is the port number on the destination host for the connection– reserved port for Telnet.

1111 is the port on the client where Netlet listens for a connection request from the first destination host sesta.

1234 is the port on the client where Netlet listens for a connection request from the second destination host siroe.

The first six fields in this rule are the same as in Basic Static Rule. The difference is that three more fields identify the second destination host.

When you add additional targets to a rule, you must add three fields, local port, destination host, and destination port, for each new destination host.


Note –

You can have multiple sets of three fields describing the connection to each destination host. Listen port numbers which are less than 2048 must not be used if the remote client is UNIX-based because low numbered ports are restricted and you must be root to start a listener.


This rule works the same as the previous rule. The Netlet provider does not display any link, but Netlet automatically starts and listens on the two ports specified (1111 and 1234). The user needs to start the client software, in this case a Telnet session that connects to localhost on port 1111 or the localhost on port 1234 to connect to the host in the second example.

Static Rule with Multiple Host Selection

Use this rule to specify multiple alternative hosts. If connection to the first host in the rule fails, Netlet tries to connect to the second host specified and so on.

Rule Name 

Encryption Cipher 

Remote Application URL 

Enable Download Applet 

Enable Extend Session 

Map Local Port to Destination Server Port 

gojoe 

SSL_RSA_WITH_RC4_128_MD5

/gojoe.html 

  • Client Port: 8000

  • Server Host: gojoeserver

  • Server Port: 8080

Select the checkbox 

  • Local Port: 10491

  • Destination Host: siroe+sesta

  • Destination Port: 35+26+491-35+491

where

10491 is the port on the client where Netlet listens for a connection request from the destination host.

Netlet tries to establish connection with siroe on port 35, port 26 and port 491 in the same order, depending on which one is available.

If connections to siroe are not possible, Netlet tries to connect to sesta on port 35 and 491 in the same order.

The plus (+) sign between hosts indicates alternative hosts.

The plus (+) sign between ports numbers indicates the alternative ports for a single destination host.

The minus (-) sign between port numbers is the separator between the port numbers for different destination hosts.


Note –

Connections to hosts provided in the chain is attempted serially. For example, if the rule is siroe+ sesta, then a connection to siroe is attempted first. If the connection fails then the connection to sesta is attempted . If the hosts listed first in the rule are physically unavailable in an active network, the time taken to connect to the next available host will increase as the number of unavailable hosts in the rule increases.


Dynamic Rule to Invoke a URL

This rule enables a user to configure the destination host required, enabling the user to telnet to various hosts over Netlet.

Rule Name 

Encryption Cipher 

Remote Application URL 

Enable Download Applet 

Enable Extend Session 

Map Local Port to Destination Server Port 

myrule 

SSL_RSA_WITH_RC4_128_MD5

telnet://localhost:30000 

Do not select the checkbox 

Select the checkbox 

  • Local Port: 30000

  • Destination Host: TARGET

  • Destination Port: 23

where

myrule is the name of the rule.

SSL_RSA_WITH_RC4_128_MD5 indicates the cipher to be used.

telnet://localhost:30000 is the URL invoked by the rule.

false indicates that no applets are to be downloaded.

Extend Session(true) indicates that the Portal Server should not time out when the Netlet connection is active.

30000 is the port on the client where Netlet listens for connection requests for this rule.

TARGET indicates that the destination host needs to be configured by the user using the Netlet provider.

23 is the port on the destination host opened by Netlet, in this case the well-known port for Telnet.

ProcedureTo Run Netlet After a Rule is Added

After this rule is added, the user must complete some steps to get Netlet running as expected. The user needs to do the following on the client side:

  1. Click Edit in the Netlet provider section of the standard Portal Server desktop.

    The new Netlet rule is listed under Rule Name in the Add New Target section.

  2. Choose the rule name and type the name of the destination host.

  3. Save the changes.

    The user returns to the desktop with the new link visible in the Netlet provider section.

  4. Click the new link.

    A new browser is launched that goes to the URL given in the Netlet rule.


    Note –

    You can add more than one destination host for the same rule by repeating these steps. Only the last link selected is active.


Dynamic Rule to Download an Applet

This rule defines a connection from the client to hosts that are dynamically allocated. The rule downloads a GO-Joe applet from the server on which the applet is located, to the client.

Rule Name 

Encryption Cipher 

Remote Application URL 

Enable Download Applet 

Extend Session 

Map Local Port to Destination Server Port 

gojoe 

SSL_RSA_WITH_RC4_128_MD5

/gojoe.html 

  • Client Port: 8000

  • Server Host: gojoeserver

  • Server Port: 8080

Select the checkbox 

  • Local Port: 3399

  • Destination Host: TARGET

  • Destination Port:58

where

gojoe is the name of the rule.

SSL_RSA_WITH_RC4_128_MD5 indicates the cipher to be used.

/gojoe.html for example is the path of the HTML page containing the applet, the path should be relative to the documentation root of the web container on which portal is deployed.

8000:server:8080 indicates that port 8000 is the destination port on the client to receive the applet, gojoeserve is the name of the server providing the applet, and 8080 is the port on the server from which the applet is downloaded.

Extended Session (true) indicates that the Portal Server should not time out when the Netlet connection is active.

3399 is the port on the client where Netlet listens for connection requests of this type.

TARGET indicates that the destination host needs to be configured by the user using the Netlet provider.

58 is the port on the destination host opened by Netlet, in this case the port for GoJoe. Port 58 is the port that the destination host listens to for its own traffic. Netlet passes information to this port from the new applet.