This issue only affects devices with three (3) or more MPC10's installed in a single chassis with OSPF enabled and configured on the device. An Insufficient Resource Pool weakness allows an attacker to cause the device's Open Shortest Path First (OSPF) states to transition to Down, resulting in a Denial of Service (DoS) attack. This attack requires a relatively large number of specific Internet Mixed (IMIXed) types of genuine and valid IPv6 packets to be transferred by the attacker in a relatively short period of time, across three or more PFE's on the device at the same time. Continued receipt of the traffic sent by the attacker will continue to cause OSPF to remain in the Down starting state, or flap between other states and then again to Down, causing a persistent Denial of Service. This attack will affect all IPv4, and IPv6 traffic served by the OSPF routes once the OSPF states transition to Down. This issue affects: Juniper Networks Junos OS on MX480, MX960, MX2008, MX2010, MX2020: 18.1 versions prior to 18.1R2-S4, 18.1R3-S5; 18.1X75 version 18.1X75-D10 and later versions; 18.2 versions prior to 18.2R1-S5, 18.2R2-S3, 18.2R3; 18.2X75 versions prior to 18.2X75-D50; 18.3 versions prior to 18.3R1-S4, 18.3R2, 18.3R3; 18.4 versions prior to 18.4R1-S2, 18.4R2.