Diff and ignore lines missing in one file
Solution 1:
You might also take a look at comm, if you have it available:
comm [-1] [-2] [-3 ] file1 file2
-1 Suppress the output column of lines unique to file1.
-2 Suppress the output column of lines unique to file2.
-3 Suppress the output column of lines duplicated in file1 and file2.
The input files should be sorted. However, you can modify the default behavior with --nocheck-order option, if available.
In your case you would want comm --nocheck-order -23 file filter_file