Patent ID: 9032524
Filing Date: 2015-05-12
Classification: H04L

Abstract:
1. A packet filtering system for mitigating denial of service (DoS) and/or distributed denial of service (DDoS) attacks against one or more applications associated with a server, the packet filtering system comprising: a first filter stored in a memory that processes received packets, the received packets having been transmitted to the packet filtering system through a network, the first filter being configured to: a second filter stored in the memory and communicatively coupled in series with the first filter, the second filter comprising: (i) a hash function that assigns hash values to packets received by the second filter; and (i) an activity table having a fixed size that is stored on a single CPU core, wherein the activity table comprises entries for the hash values indicating whether a received packet belongs to a valid session, wherein the second packet filter is configured to: a protocol stack interface configured to: