+/** Stores a cached ban entry.
+ * Each ban has one of these hashed in a hash_map to make for faster removal
+ * of already-banned users in the case that they try to reconnect. As no wildcard
+ * matching is done on these IPs, the speed of the system is improved. These cache
+ * entries expire every few hours, which is a reasonable expiry for any reasonable
+ * sized network.
+ */