Problem:

When creating the Enterprise Manager Database Control repository, the following error is displayed:

SEVERE: Failed to allocate port(s) in the specified range(s) for the following process(es): 
JMS [5540-5559],RMI [5520-5539],Database Control [5500-5519],EM Agent [3938] | [1830-1849]

Solution:

Ensure that the IP address and hostname are correctly set, as well as the ORACLE_HOSTNAME environment variable.