Black holes are places in the network where incoming or outgoing traffic is silently discarded without informing the source that data did not reach its intended recipient.

Such attacks can only be detected by monitoring the lost traffic

Some Solution/rules to detect blackhole attack

1. Black hole filtering: dropping packets at the routing level, usually using a routing protocol to implement the filtering on several routers at once, often dynamically to respond quickly to distributed denial-of-service attacks.

2. A DNS-based Blackhole List (DNSBL) or Real-time Blackhole List (RBL) is a list of IP addresses published through the Internet Domain Name System (DNS) either as a zone file that can be used by DNS server software, or as a live DNS zone that can be queried in real-time. DNSBLs are most often used to publish the addresses of computers or networks linked to spamming; most mail server software can be configured to reject or flag messages which have been sent from a site listed on one or more such lists. The term "Blackhole List" is sometimes interchanged with the term "blacklist" and "blocklist".