On InfoSec Community Forums people quoting that receiving reports of SNMP scans that shows attempt of DDoS cyber attacks against Google’s public recursive DNS server.
Users have observed that attacks started at 2014-09-14 21:35 UTC with interval of every 20 minutes.
The SANS Internet Storm Center investigating the scale of attack.Simple Network Management Protocol (SNMP) is used for collecting information from, and configuring, network devices, such as servers, printers, hubs, switches, and routers on an Internet Protocol (IP) network.
On infosec Forum reads like someone trying to break the internet with large query possibilities of SNMP protocol to attack misconfigured gateways ;
It appears someone is trying to brick devices, not conduct a reflection attack. We are also seeing our entire IP range hit. For each class C range the IP address being targeted increments by 1 every 20 minutes. They are attempting to set ipDefaultTTL to 1 and ipForwarding to 2 (not forwarding), using a community string of “private”