You could go though each of the items (the key value pair) in the dictionary and add them into a result dictionary if the value was not already in the result dictionary.
input_raw = {112762853378:
{'dst': ['10.121.4.136'],
'src': ['1.2.3.4'],
'alias': ['www.example.com']
},
112762853385:
{'dst': ['10.121.4.136'],
'src': ['1.2.3.4'],
'alias': ['www.example.com']
},
112760496444:
{'dst': ['10.121.4.136'],
'src': ['1.2.3.4']
},
112760496502:
{'dst': ['10.122.195.34'],
'src': ['4.3.2.1']
}
}
result = {}
for key,value in input_raw.items():
if value not in result.values():
result[key] = value
print result