D2 crucible and DoS, MTU, Port Forwarding, and Latency issues. D2 has the same issues as D1. The game is a P2P, they threw in the term 'hybird network architecture cloud based server.' But in reality Mobility and Ability are ran on the P2P connection, game items (loot) and player progression are ran on the 'hybird server.' Aka nothing changed. Peer to Peer (P2P) Has one console as host, everyone else communicates through the host, and every player has 2 connections to bungie servers for meta data. A= host, B= Player 1 (not host), C= Player 2 (not host). Player B shoots player C. Packet flow goes from B to A, A to C, C to A, A to B. I've heard a lot of players claim they have been DDoS'ed but there is not evidence to support the claim. DDoS'ing would be noticed by your ISP and LEC and referred to the FBI as a cyber crime. I've been DoS attacked. DoS attacks are performed in two ways when it pertains to Crucible in D2. 1.) Host of the game DoS their own router, sometimes it's as simple as streaming video like Netflix. 2.) The attacker gets your IP address and sends a large packet targeting your Console to cause a buffer overflow and crash. What it looks like depends on your home network. If you have suffecent BW and your router can handle it, the only thing that will crash is your console. But by the crash of the console you can't directly tell if it is a Memory leak or a DoS. You need to capture and do analysis of the data. Destiny 2 - Playstation 4 TCP: 1935,3478-3480 UDP: 3074,3478-3479 Destiny 2 - Xbox One TCP: 3074 UDP: 88,500,1200,3074,3544,4500 Destiny 2 - PC UDP: 3074,3097 When I was DoS attacked it targeted UDP port 3074 on the transport layer. They sent a 5 Gb packet from a third party website causing my PS4 to buffer overflow and crash. My ISP was 100Mb up/dn 1-5ms of latency and I have a Cisco enterprise router. The only device affected was my PS4. If your ISP doesn't have as much bandwidth (BW) or you have a lower quality router your router may crash as well. The actual data is not important, it's the size. The data packet sent to me just contained a repeated sequence of numbers. Because Every player in a P2P gets everyones IP address this could have been done by anyone in that group. In my case I was the second to last player in the game, so it was obvious whom was the DoS'er-never recieved a ban. Why a VPN will not prevent a DoS attack? VPN 1.1.1.1 still fwd all packets to you 2.2.2.2. In this case marked for the Console via UDP port 3074. VPN protect you from being directly hacked but have no effect on a DoS attack. What are MTU issues? Maximum Transmit Unit (MTU) establishes the packet size and largely are affected if fragmentation is not allowed. If fragmentation is not allowed any packet larger than the set MTU is dropped. With fragmentation, the packet has to be stored to memory (buffered) then repacketed at the MTU size. A=host, B=1500 Mb , C=1408 Mb and B shoots C. Packet flow is 1500Mb from B to A, A buffers and sends 2 packets 1408Mb to C, 1 packet 1408 Mb C to A, A to B 1 packet 1408 Mb. What MTU looks like in gameplay when you're affected? Not everyone will load on the Map. Ever take on a guy or 2v1 and win both only to have 2 more enemies magically appear out of nowhere!? If the MTU issues are bad enough, you will not be able to damage anyone unless you have an area effect damage. Aka pulse grenade, most supers with splash damage, etc. Sometimes the game bugs out causing this same issue. What it looks like when a target has an MTU issue? You empty your entire clip into the guy and the rounds go through their body and never register. What is happening? If you are not loaded into their game you can not damage them. Sometimes you can load and register then by movement unload from their map giving the appearance of the person taking more damage. Again area damage seems to get by this issue by loading the area effect damage onto the map. Port Forwarding As stated above port forwarding needs to be enabled for mentioned TCP and UDP ports for your Console or PC or you can experience several network related issues from dropping packets. Several are referring to this as NAT type. In reality, there are two types of translations used, NAT and PAT. NAT is Public to Private IP space translation and PAT is Public to Port Translation. This can be handled by your Router, Modem or by your ISP. On your personal Modem/Router make sure port forwarding is enabled for the required ports to rule you out as the issue. Latency Issues rule crucible! What it looks like: Dying around corners, players not registering, players appearing in locations that they are not, players in God Mode... The real issue becomes the stacking of latency in P2P. On a dedicated server each player there is one element, you to the server. In P2P it is (You to the host + host to other players). In a game where everyone is at 200ms latency good luck. Players with high latency will move faster than their abilities allow, sometimes won't register because you are shooting at where they were a half second ago and the game has them to the new spot. What it's like playing with high latency, movement is everything. If you camp you will die sometimes before they appear on the map. If you move constantly and changing direction you are as close to god mode without technically cheating. In my case, my K/D drops fast... The sad part is almost all these issues would be solved with dedicated servers... Extra.. Modified controllers and you have Modified Consoles because people love to cheat and tell you to get gud. They will hardly ever admit it and Bungie will rarely do anything about it.