DayZ Server DDoS and Uptime

DayZ downtime is not one failure. The process can crash, the host can reboot, the route can be attacked, or the provider can null-route the IP because the attack and the game look similar to a nervous filter. Players experience all four as "server dead" and they go to the next line on the roster. Your job is to know which failure you had, because the fix is different.

A crash loop is a file problem: a bad mod, a full disk, a corrupted persistence write. Read the log before you reinstall SteamCMD. CFTools Architect keeping the process supervised is what turns a crash into a restart instead of a server that stays down until you wake up. CFTools Cloud is where you see that the restart happened and where you tell players, if you have RCon, that you know. Cloud is not a magic shield. It is management. If the IP is blackholed upstream, neither product can invent a route.

UDP game servers get scanned. Some of that noise is harmless. Some of it is an attack aimed at the game port or at the machine. A provider who has never hosted games will mitigate by making you unreachable. Ask before you buy. The provider checklist includes that question because it is the one that matters at 9 p.m. Saturday. Moving IP after an attack means updating every launcher favorite and waiting for the CFTools crawler to see the new address. Warn people. A silent IP change looks like a dead server that left a ghost listing until the old one ages out.

Uptime inside the mission is the other number. A process that stays up while the simulation stalls is not up. Players call it desync and they are right that the server is failing them. That is CPU, mods, and entity count, covered in requirements, not a firewall rule. Watch a real session. The player chart on a DayZ Manager server page is the public version of "were people able to stay." A chart that falls off a cliff every night is a restart or a crash. A chart that never rises is a population problem, not an attack.

Backups are part of uptime. If the only copy of persistence is on the machine that just died, the wipe was not scheduled and you do not get to call it a fresh start without losing trust. Copy the hive and the storage somewhere else. Test the copy. The persistence guide is the file list. A backup you cannot restore is a comforting file name.

Do not run your own "DDoS protection" by closing the query port. You will vanish from the index and from honest browsers, and the attacker who wanted the game port will not be impressed. Keep UDP open for the ports in the firewall guide. Rate-limit carefully if you know what you are doing. Guessing with iptables during an attack is how you lock out your own RCon and cannot kick anyone while you debug. Leave a path for Cloud or you will be standing in a remote desktop that is also timing out.

Separate the outage you can see

When the server dies, write one line before you change anything: process down, process up but empty, or process up and unplayable. Those are three fixes. A crash loop is the log and the last mod. A null-route is the provider, and restarting the binary will not create a route. Desync with a full player count is CPU and entities, and a firewall rule will not add clock speed. The player chart on your server page tells you which shape it was, after the fact. Look at it before you rebuild the machine out of frustration.

Ask the provider, on a calm day, what they do with a UDP flood to a game port. "We null-route" means your community will vanish for a while, and you should know the while. "We have game-aware filtering" is a better sentence if it is true. You will not know it is true until the first bad night, so prefer a host that has hosted games before. CFTools Architect is a DayZ host, not a generic VM that met UDP yesterday. It is still not a magic shield. Say that to your players so they do not expect Cloud to eat an attack. CFTools Cloud manages the process that is reachable. Unreachable is a network ticket.

Keep a path to the machine that does not depend on the game port. If RCon and SSH and the panel all die together, you are waiting on the provider anyway. If only the game port dies, you can still announce in Discord. Do not "fix" visibility by closing the query port. You will drop off the community list and the country list and the attacker will continue. Stay listed, stay reachable, and let the host filter.

Backups are uptime for the world, not for the process. A machine that returns in five minutes without persistence is a wipe. Copy the hive off-box. Test the copy. A modded server with a week of bases is a week you cannot recreate from memory. The chart can look healthy right up until the disk dies. The chart is not a backup. It is a picture of players who will not wait while you learn that.