delete duplicate rows with awk files

Linux and Unix-Like Ubuntu
1

Hi every body

I have some text file with a lots of duplicate rows like this:

165.179.568.197
154.893.836.174
242.473.396.153
165.179.568.197
165.179.568.197
165.179.568.197
154.893.836.174

how can I delete the repeated rows?

Thanks
Saeideh

2 
sort -u file_name
3

sort filename | uniq -d