After updating serverB’s network configurations， an administrator notices that serverA， which resides in a different subnet， is unable to communicate with serverB via ssh or telnet. As ping’s to the server fail， the administrator logs onto serverB via a console and finds an available interface en0 in the ’up’ state. From the console connection， en0 can communicate with other servers in the same subnet. What is the most likely cause of the problem？（）