Troubleshooting JMeter remote testing issues

This issue revolves around JMeter remote testing.  I currently have a Windows master machine running JMeter tests remotely on a Linux (redhat) slave machine.  All properties were changed and connections were successful (until a power outage happened which caused remote connections to fail).

There were two issues were:

1. Since the power outage, all machines were rebooted.  Unknowingly, Redhat Linux has a default firewall.  Run iptables on command prompt to check for firewall. The firewall blocks any remote connections attempted on the server.
2. After connecting successfully to the slave machine, an issue where the JMeter GUI not responding with test results occurred. I was not able to tell whether a test was being run or completed at all unless I looked from the cmd window. This issue ended up being a network issue. The slave machine was responding (marked in the command line) and the remote JVM memory monitor was also increasing, but there was still no response. As a matter of fact, the responding server got lost in the network connection. The master machine was able to connect to the slave, but the responding data got lost in the master's network. The master machine has multiple network connections, and the server was sending data back to a network that the JMeter client wasn't on. As a workaround, I had to disable networks that were not being used at that moment.

Since this is just a workaround, it would be nice to figure out how to specify a network to open JMeter instead of randomly assigning this variable. Any comments or suggestions are appreciated.