Cristian, You have a basic network problem. You have a single name, RHEL, which points to two IP addresses, 10.9.6.160 and 10.9.0.188. That won't work. The /etc/hosts file is searched sequentially so it always finds the first occurrence of RHEL.
By default, any process that listens on all interfaces will listen on the loopback interface ( 127.0.0.1). You have an additional problem and that is that wherever you go, your IP address is going to change. There is a document on the subject, RFC 1918. Basically, any IP address that begins with 10., 172.12 through 172.31, and 192.168 is a private address. You're getting the 10.9.6.180 and 10.9.0.188 addresses from the network, and that's unusual but perfectly legitimate. If you are only going to use these two addresses, then what you can do is add the following to your /etc/hosts file: # wireless 10.9.6.160 RHEL6_wireless # wired 10.9.0.188 RHEL6_wired When your systems attempt to connect to the wired IP address and you are running in wireless mode, then the connection attempt will fail and the map/reduce software won't send any work to. Similarly, if you attempt to connect to the wireless IP address and you are wired. Jeff Silverman Google
