The details of why following commands are done is beyond the scope of this wiki but a good starting point is the wiki http://wiki.jboss.org/wiki/Wiki.jsp?page=JGroupsWiresharkExample. Here are configurations you need to do be able to run two node JBoss AS cluster in fedora box. You need to be root user to run these commands.

Add two IP addresses to the same NIC.

  root@localhost bin]# /sbin/ifconfig eth0:1 192.168.148.143
  root@localhost bin]# /sbin/ifconfig eth0:2 192.168.148.144

Add these commands in /etc/rc.local if you want these to survive reboot

Let all udp messages through

/sbin/iptables -I RH-Firewall-1-INPUT 5 -p udp -d 224.0.0.0/4 -j ACCEPT

Enable UDP point to point message

/sbin/iptables -I RH-Firewall-1-INPUT 9 -p udp -s 192.168.148.0/24 -j ACCEPT

Enable TCP  message

/sbin/iptables -I RH-Firewall-1-INPUT 10 -p tcp -s 192.168.148.0/24 -j ACCEPT

Make sure it survives reboot

/etc/init.d/iptables save

You should see a confirmation message:

iptables: Saving firewall rules to /etc/sysconfig/iptables:[OK|  OK  ]

Your ip table should look more or less like this

[root@localhost prabhat]# /sbin/iptables -L -n -v
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination        
47705   34M RH-Firewall-1-INPUT  all  --  *      *       0.0.0.0/0            0.0.0.0/0          

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination        
    0     0 REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT 48822 packets, 17M bytes)
 pkts bytes target     prot opt in     out     source               destination        

Chain RH-Firewall-1-INPUT (1 references)
 pkts bytes target     prot opt in     out     source               destination        
10534   11M ACCEPT     all  --  lo     *       0.0.0.0/0            0.0.0.0/0          
   11   924 ACCEPT     icmp --  *      *       0.0.0.0/0            0.0.0.0/0           icmp type 255
    0     0 ACCEPT     esp  --  *      *       0.0.0.0/0            0.0.0.0/0          
    0     0 ACCEPT     ah   --  *      *       0.0.0.0/0            0.0.0.0/0          
    0     0 ACCEPT     udp  --  *      *       0.0.0.0/0            224.0.0.0/4        
  482 70505 ACCEPT     udp  --  *      *       0.0.0.0/0            224.0.0.251         udp dpt:5353
  327 65727 ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:631
    0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:631
    0     0 ACCEPT     udp  --  *      *       192.168.148.0/24     0.0.0.0/0          
    0     0 ACCEPT     tcp  --  *      *       192.168.148.0/24     0.0.0.0/0          
35669   22M ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
  682 85394 REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited 

Verify that jgroups work

• Get jgroups.jar. You can find this jar in JBossAS/server/all/lib as well as many other places.

• Open a shell (A) and run

[prabhat@localhost lib]$ java -cp jgroups.jar org.jgroups.tests.McastReceiverTest -bind_addr 192.168.148.143 -mcast_addr 224.10.10.10 -port 5555

• open another shell(B) and run

java -cp jgroups.jar org.jgroups.tests.McastSenderTest -bind_addr 192.168.148.144 -mcast_addr 224.10.10.10 -port 5555

At prompt, enter some texts for example: prabhat . You should see the message in shell A. Now you can use your laptop to test

• session replication

• fail over

• apache load balancing etc

Many thanks go to Richard Achmatowicz !!