Highly Performant & Scalable Ultima Online Server Emulator
https://www.modernuo.com
c-sharpcsharpcsharp-coredotnetdotnet-coreemulatorgplgplv3mmommo-enginemmorpgmmorpg-serveronlinerpgrunuoserverservuoultimaultima-onlineuo
## Breaking Changes * The Firewall and IP Limiter have been rewritten. Please read the notes carefully! * `TcpServer.Instances` moved back to `NetState.Instances` - sorry - it was stupid to move it to begin with. > [!Note] > Sockets that fail the IP Limiter or Firewall will be immediately and forcibly disconnected. > This means they will be stuck at "Verifying account..." if it was a real client. ### Summary - Removes firewall wildcard support. - Removes `AccessRestrictions`. - Moves Firewall/IPLimiter to the core. - Moves `TcpServer` to its own thread. - Removes the `SocketConnect` and `SocketDisconnect` event sinks. - Moves `Instances` back to `NetState.Instances`. - Fixes a long standing bug with bad handling of duplicate listener addresses. #### Firewall The firewall has been completely rewritten. There is now an "Admin Firewall" which saves to the config file. Secondarily, there is an internal firewall used exclusively by the TcpServer while processing sockets. The Admin firewall mirrors it's additions/deletions to the internal firewall by adding requests to a queue. > [!IMPORTANT] > **Wildcard firewall entries, such as `X`, `*`, `?` are not allowed.** > **Ranges in between IP classes or sextets are not allowed.** > **Please make sure to use one of the following:** > * IP Address - `192.168.1.1` > * CIDR - `192.168.1.0/24` > * Range - `192.168.1.1-192.168.1.100` #### IP Limiter The IP Limiter has been completely rewritten. The available configurations are: ```json "ipLimiter.enable": "True", "ipLimiter.maxConnectionsPerIP": 10, "ipLimiter.clearConnectionAttemptsDuration": "00:00:00:10", "ipLimiter.clearThrottledDuration": "00:00:02:00", ``` The IP Limiter is set up to prevent spamming connections from the same IP. Every time an IP connects, it is added to a connection list. After 10 attempts, the IP is added to the throttle list. To keep the system fast, the connection list is entirely wiped every 10 seconds, and the throttle list is entirely wiped every 2 minutes. |
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| .config | ||
| .github | ||
| Distribution/Data | ||
| docs | ||
| Projects | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| azure-pipelines.yml | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| Directory.Build.props | ||
| FAQ.md | ||
| global.json | ||
| LICENSE | ||
| mkdocs.yml | ||
| ModernUO.sln | ||
| publish.cmd | ||
| publish.sh | ||
| README.md | ||
| rider-settings.zip | ||
| Rules.ruleset | ||
| RUNUO_TO_MODERNUO.md | ||
| SPONSORS.md | ||
| stylecop.json | ||
| THIRD-PARTY-NOTICES | ||
| version.json | ||
ModernUO

Ultima Online Server Emulator for the modern era!
Requirements
Supported Operating Systems
Required Frameworks
All Operating Systems
Windows
Development
Supported IDEs
Getting Started
- Install prerequisite requirements
- Clone this repository (or download the latest):
git clone https://github.com/modernuo/ModernUO.git
- Open
ModernUO.slnto start developing
Building/Publishing
- Run
./publish.cmd [release|debug (default: release)] [os] [arch (default: x64)]os- Supported operating systemswin- Windows 10/11/2019/2022osx- MacOS 11/12/13 (Big Sur, Monterey, Ventura)linux- Linux
archx64- Intel 64-bitarm64- ARM 64-bit (Windows Arm64 not supported)
Linux Prerequisites
Fedora, CentOS, RHEL, etc
dnf upgrade --refresh -y
# CentOS does not come with EPEL enabled
dnf install -y epel-release epel-next-release
dnf install -y findutils libicu zlib-devel zstd libargon2-devel tzdata
Ubuntu, Debian, etc
apt-get update -y
apt-get install -y libicu-dev libz-dev zstd libargon2-dev tzdata
Running the Server
- Follow the publish instructions
- Run
ModernUO.exeordotnet ModernUO.dllfrom theDistributiondirectory on the
Troubleshooting / FAQ
- See FAQ
Want to sponsor?
Thank you for supporting us! You can find out how by visiting the sponsors page.
Collaborators
Thanks
- RunUO Team & Community
- Voxpire, the ServUO Team & Community
- Karasho, Jaedan and the ClassicUO Community



