The normal MTU size is 1500 bytes of data on an Ethernet connection or 1492 bytes on PPPoE. The allegations that I've heard thus far, is that this is the new method since Trials deployed, in which enemies are gaming the system in order to make their character harder to kill or invincible. The first bit of the research was to launch google and I noticed a lot of Italians were using it as an exploit and posting videos to youtube. A sources of older game play using the exploit~ [url]https://youtu.be/czyRhHaGwrU[/url] You will notice the player can not see enemies nor can the player be hurt or killed. The player did this by altering his PS console network MTU rate to 600 down from the original 1500 byte rate. [b]So what exactly is MTU[/b] MTU stands for Maximum Transfer Unit and it is a setting that limits the maximum size of a network packet. Back in the early days of communication devices had to know the maximum data rate the other device could handle to maximize the throughput of the system. Larger files could be fragmented into smaller units in order to be transmitted by different mediums. [b]How is MTU applied in Crucible of Destiny[/b] Crucible is not server based, it is a series of Peer to Peer (P2P) connections, you have one host and everyone else is connected to that host via a peer connection. So I shoot the host in crucible-- my packet goes to the host of the game and is applied, this will be the lowest latency of that match. I attack a non-host player and my packet goes to the host then is forwarded to the non-host player console. [b]When the host has a low MTU[/b] All players in the game can be green bar with the destiny server but the game content will appear glitchy and lag, all players will take more damage than normal excluding one shot kill weapons like snipers and high impact shotguns. You will get the feeling that your shots are not registering. Your system has to work more in order to fragment and comply with the MTU. [b]When a non-host player has a low MTU[/b] Those players with a low MTU will sometimes appear glitchy and lag, they will take more damage than normal from non-high impact weapons and snipers. You will feel like your shots are not registering. The host system has to work harder on fragmenting and complying with the non-host players lower MTU. [b]What a severly low MTU player looks like in Trials of Osiris[/b] Note the players can not be killed and can capture the zone as in the first link above. [url]https://youtu.be/MLRDWxKZpq8[/url] [b]How is MTU usually done in a crucible match[/b] Each P2P connection sends a top down fashion to find the maximum rate for each P2P connection, then sets that as the assigned MTU for each if you are the host. If you are not the host of the match it will only negotiate one P2P connection. Over a course of a match those rates change over time. [b]How MTU is done with a fixed assigned manually value[/b] Simply it is the assigned value, no need to negotiate with other P2P and if a lower MTU is on another connection your system will fragment your datagram into smaller units. [b]What happens if the datagram segments are larger than the MTU[/b] The system actual communication ports mark the data as jabber, most systems auto detect this and block traffic until the segments are again inline with the MTU. [b]So what is the exploit[/b] Changing the MTU rate is altering the throughput of a network. Throughput is the actual data sent as bandwidth is the maximum amount that can travel. Well the game itself needs a certain amount of the data just to load and run and in the case of the first video the player found an MTU rate that allowed that "cheater" to load the game and not any other player. [b]So this does show that it is an exploit of the game[/b]. Referencing other sources, as the MTU is increased it allows more content to load as some allies and enemies. Note that MTU is variable to each system, a set MTU for one person could be a different value to cause the same effect on another system. Thus applying a variance of the MTU allows a player to control what can load in a gaming atmosphere on their system. [b]So what is the claim glitch [/b] If a player alters their MTU, only the players that are loaded in his system can cause damage to that player. While indicating the player is a green bar. Basically taking advantage of the throughput to control and limit engagements. If one were to play with the values to where only a few players could load, then ran with team mates using the same settings, they would always have a 2v1 or 3v1 before the next player could load and cause damage. Giving the appearance of a player taking more damage than a max armor ram warlock with radiant skin and a flame shield. ---Side note that needs to be nerf'ed!!! Full clip to take down half a shield... who is the idiot at Bugie that thought of that. Of the main hacks, this is the one that is overly being used in the last few months as the crucible system continues to be a lagfest. The main exploits are lagswitch, host UDP flooding his router to lag everyone out, MTU mod, and scripts being loaded into modified controllers to auto assist a player. These evolve everyday but are centered on the fact the system is P2P and all but the script kiddies on modified controllers would be solved by dedicated servers. Hopefully this information is useful for Bungie to resolve the issue by requiring a minimum MTU rate in order to play in the PvP environment and/or gives them greater cause to seek and outsource a dedicated server platform. Bungie you can not make PvP a primary part of the game if you are unwilling to fix the most basic design faults! Take Care and Good Luck gaming [b]EDIT1[/b] Looking into the P2P on crucible you actually do have a connection with each player, the majority of the traffic goes to the host. From looking at those P2P communication it appears to only be used in determining the host. I will try to make time to capture some data next month and trace the data packets that indicate a shot and the communicated hit markers received. [b]EDIT2[/b] I can not test this exploit/glitch, as I'm currently in a dorm building on Public high speed WiFi internet that is included in the rent due to being a contractor. Thus no access to the router and the huge volumes of traffic make it hard to capture. I'm also not allowed to manipulate it due to my clearance in the field as it would be a breach. All I can do is post the information, monitor reactively with a packet sniffer and hope Bungie changes it's parameters to require a minimum MTU that allows the PVP match to act as intended.