Restricting the dynamic port range on AIX
 Technote (troubleshooting)
 
Problem(Abstract)
By default IBM® WebSphere® Application Server opens a port for internal socket communications. It uses the new ServerSocket Java™ API to open this port. The ServerSocket API will dynamically select an available (unused) port in a range between 32768 to 65535.
 
Resolving the problem
To list the port range, enter the following command.
/usr/sbin/no -a | fgrep ephemeral

You can change this to your own range:
/usr/sbin/no -o tcp_ephemeral_low=49152 -o tcp_ephemeral_high=65535

This configures the port range as 49152,65535. Ports created by WebSphere Socket will be within this specified range.

The attached two Java testcases will set the port range to the original range values again. The dynamic_port_test1.java program has a port range of 32768,50500 and the dynamic_port_test.java program has a port range of 50501,65535.

Running dynamic_port_test will create a random port between 50501,65535.

Running dynamic_port_test1 will create a random port between 32768,50500.

 
dynamic_port_test1.javadynamic_port_test.java
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
Historical Number
63376
487
000
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > System Management/Repository
Operating system(s): AIX
Software version: 6.0
Software edition:
Reference #: 1239030
IBM Group: Software Group
Modified date: Jun 2, 2006