diff --git a/libs/firewall.py b/libs/firewall.py
index 88b03d8..68b852d 100644
--- a/libs/firewall.py
+++ b/libs/firewall.py
@@ -33,4 +33,14 @@ def generate_ip_list_from_routes(filename):
 named_networks = {
     'versatel': generate_ip_list_from_routes('as8881'),
     'telekom': generate_ip_list_from_routes('as3320'),
+    'rfc1918': {
+        'ipv4': {
+            '10.0.0.0/8',
+            '172.16.0.0/12',
+            '192.168.0.0/16',
+        },
+        'ipv6': {
+            'fc00::/7', # actually RFC 4193, but good enough here
+        },
+    },
 }