bash-5.3:/# du -sh /var/log/pdns.log
8.3G /var/log/pdns.log
it seems that i forgot to disable verbose logging⌠in may
#SERVFAIL
so i look into why my logs are so enormous. i shouldnât have left them as verbose for 1.5 months but they also shouldnât have grown to EIGHT GIGABYTES. and most of my recent log lines are something like
Jul 04 13:36:22 msg="Limit of simultaneous TCP connections reached - raise max-tcp-connections" prio="Warning"
this, but 15 times a second⌠Which usually means that weâre under attack. but itâs a very lousy attack, i canât even see it on the graph, so theyâre only really causing some disruption to TCP connections, not UDP. and most of DNS is UDP, thatâs why Iâm only noticing right now.
anyways. ss -tulnap | grep 53 shows a lot of connections with addresses that begin with 2a03:2880. | wc -l says 273, from maybe 5-6 different hosts. and, my dear comrades, can you guess who owns 2a03:2880::/32?
inet6num: 2a03:2880::/40
netname: PRN
country: US
admin-c: RD4299-RIPE
tech-c: RD4299-RIPE
status: ASSIGNED
mnt-by: fb-neteng
mnt-by: facebook-neteng
created: 2020-03-11T00:33:38Z
last-modified: 2020-03-11T00:33:38Z
source: RIPE
thatâs right! facebook! and after a preliminary check, weâve seen this same exact thing on at least one other #SERVFAIL nameserver
in âcompletely unrelated newsâ: i âslippedâ in my kitchen and executed ip6tables -I INPUT -s 2a03:2880::/32 -j DROP as root on sakamoto iâm so sorry (not sorry). and through the power of ip6tables⌠suddenly my TCP limits arenât reached anymore. CURIOUS
if you didnât have enough reasons to hate meta: FUCK META 
@domi and they donât even seed their torrents anyway âhelene
@makdaam getting on my nerves REALLY badly. that /32 is all of their IPv6, I donât want to bother with blocking all of their v4 too; since they were happy to send 270 connections to my pdns limited to 50 TCP conns, I think they literally wonât notice the block and will continue sending packets (i.e. they wonât fallback to IPv4, hopefully)
@domi i had the same thing happen to me an built a AS blochlist service, but using nftablesđ
https://codeberg.org/stura-htw-dresden/stura-infra/src/branch/master/modules/isp-block.nix
Because the semrush but was alsmost worse for međ
@domi They're not the first bigcorp to flood some service with requests. Google with goproxy DDoSing git repos is a good example from the past. All the AI crap is the most current one.
I'm wondering if having a community maintained prefix list or AS list to just drop is something that would be useful (prefixes probably more since most people can add firewall rules).