diff --git a/openbsc/tests/bsc-nat/prefixes.csv b/openbsc/tests/bsc-nat/prefixes.csv
new file mode 100644
index 0000000..0b66ffe
--- /dev/null
+++ b/openbsc/tests/bsc-nat/prefixes.csv
@@ -0,0 +1 @@
+0172,0049