Peace, Here's to confirm that the pattern reported before in NANOG was indeed a reflection DDoS attack. On Sunday, it also hit our customer, here's the report:
https://www.prnewswire.com/news-releases/root-cause-analysis-and-incident-report-on-the-august-ddos-attack-300905405.html tl;dr: basically that was a rather massive reflected SYN/ACK carpet bombing against several datacenter prefixes (no particular target was identified). -- Töma On Sat, Aug 17, 2019, 1:06 AM Jim Shankland <na...@shankland.org> wrote: > Greetings, > > I'm seeing slow-motion (a few per second, per IP/port pair) syn flood > attacks ostensibly originating from 3 NL-based IP blocks: 88.208.0.0/18 > , 5.11.80.0/21, and 78.140.128.0/18 ("ostensibly" because ... syn flood, > and BCP 38 not yet fully adopted). > > Why is this syn flood different from all other syn floods? Well ... > > 1. Rate seems too slow to do any actual damage (is anybody really > bothered by a few bad SYN packets per second per service, at this > point?); but > > 2. IPs/port combinations with actual open services are being targeted > (I'm seeing ports 22, 443, and 53, just at a glance, to specific IPs > with those services running), implying somebody checked for open > services first; > > 3. I'm seeing this in at least 2 locations, to addresses in different, > completely unrelated ASes, implying it may be pretty widespread. > > Is anybody else seeing the same thing? Any thoughts on what's going on? > Or should I just be ignoring this and getting on with the weekend? > > Jim >
