On 12/15/17, Jeffs said the following...
I recall when I setup IP blocking in BBBS. I had some 13,000 IP's
blocked. I have 22 nodes available in BBBS and BBBS was getting telnet
hit constantly for a time. I have swithch over to using iptables on the
BBBS machine to manage the telnet hits.
If you're working with multi-kilobyte blocklists I'd recommend one of ipset's hash table modules if your setup supports it. Especially if you're dynamically adding rules. It'll condense down a large number of addresses or nets to a
much smaller hash that the network filter then only has to perform a hash comparison on, instead of iterating down the entire list for every packet that hits the interface. You also don't have iptables pulling and pushing the
entire ruleset back to the kernel every time you add one address.
--- Mystic BBS v1.12 A36 2017/12/03 (Linux/64)
* Origin: Subcarrier BBS (21:2/140)