I get a java.net exception, how do I fix it?

There is something wrong with your network configuration.

1. On linux check /etc/hosts doesn't have 127.0.0.1 mapped to your host name

2. check your ip address is reachable from the client, try pinging the server/client from the other machine

3. Try telnet host port, e.g. is jndi visible - telnet serverip 1099 or UIL2 - telnet serverip 8093

4. Check your dns/dhcp setup, has your lease expired.

5. nslookup will help you get a host name from an ip address to check reverse resolution - do the server and client agree about which host binds to which ip address?

6. Try tracing the route to the server - traceroute serverip

7. Is there an firewall in the way?

8. Use netstat to see what ports are open and bound to where, e.g. netstat -an

9. Do you have multi nics (network interface cards), are you multi-homing? Are the services bound to all of them?

10. Add the folllowing log4j.properties to the client which will produce a log showing where the client thinks it is connecting to

log4j.rootCategory=INFO, Default

log4j.appender.Default=org.apache.log4j.FileAppender
log4j.appender.Default.File=jbossmq.log
log4j.appender.Default.layout=org.apache.log4j.PatternLayout
log4j.appender.Default.layout.ConversionPattern=%d %-5p [%c(1)] {%t} %m%n
log4j.appender.Default.Append=false

log4j.category.org.jboss.mq=TRACE#org.jboss.logging.XLevel

Running this code on the client or server will help you understand what java thinks is your hostname/ip address

import java.net.InetAddress;
public class WhatIsMyAddress
{
   public static void main(String[] args) throws Exception
   {
      System.out.println(InetAddress.getLocalHost());
   }

}

Are you accidently discovering the wrong server using jboss's HAJNDI? Try adding the following to your jndi properties to disable discovery of a jboss server on your network.

jnp.disableDiscovery=true