I was surprised to find that a guide didn't exist on here for setting up and running dedicated servers, so here it is!

Setting up a dedicated server can be difficult without knowing a few things so this guide is to make it quick and easy to get servers up and running.

Using the default ports means that you can run 1 server but cannot join it from the same machine.

Using custom ports means that you can run more than one server from the same machine and also means that you can join the server from that same machine.

Here's all you need to do, from start to finish to get a server up and running if you don't want to read the whole guide.

1) Download the Aliens vs. Predator Dedicated Server from Steam In the Tools section.
It is approx 1.5GB (installs to about 2.3GB) and you don't need to install the actual game (unless you want to play also). You don't even need to own the game to run a server!

2) Right click on the option for Aliens vs. Predator Dedicated Server in the Tools menu once it is downloaded and click Properties.
Choose the Local Files which lets you view the files in their folder location and this will open up an explorer window so you can deal with the files and make a default.cfg file

3) You need to make a notepad .txt file on your desktop and call it default.txt as once we have finished it we will rename it to default.cfg - so in other words right click anywhere on the desktop and click New Notepad File then rename it to default.txt

4) Open the notepad file and paste the following into it

// Example default.cfg

servername "Server Name Here" // Server Name
rconpassword Password // Set Server Password
maxplayers 18 // Set the maximum number of players allowed in the server
motd "This is a default message!" // Display a message to players when they connect to your server

// Set your ports, replace xx with any two numbers, ports must be unique for each server you run on a machine. Delete the "270xx" to leave the ports at their default values.
authport 270xx
gameport 270xx
lobbyport 270xx
updateport 270xx

// Jungle = map name, DM = game type, tl = time limit, and sl = score limit.

addmap Jungle DM tl=15 sl=20 // MUST be used to create map rotation before using the "host" command

// Set species ratios: Given in this config, for each 1 Predator there can be 2 Marines, For each 1 Predator there can be 3 aliens and so forth.

predatorratio 1 // Any Value 1-4, relative to other species
marineratio 2 // Any Value 1-4, relative to other species
alienratio 3

// Set auto-balancing and friendly fire. 0 = False, 1 = True

speciesbalancing 1 // Enable or Disable auto-balancing for species
teambalancing 1 // Enable or Disable auto-team balancing
friendlyfire 0 // Enable or Disable Friendly Fire

autostartonallready 1 // Auto-Start matches when all players are ready, 0 = False, 1 = True
autostarttime 120 // Lobby Auto-Start Timer (In Seconds)
host // Start Hosting the Server, server will not show up in any list without this command!

//End configuration

5) Make any changes you want to the example and then save it.
Now copy the default.txt file and paste it on the desktop and rename the copy to default.cfg.
Copy default.cfg and paste it into your explorer window that we opened in step 2.

6) If you run the Aliens vs. Predator Dedicated Server from the Steam Tools menu now, you will get a command prompt that shows your avp server running.
It won't be visible to people looking on the Steam servers list unless you open the ports.

Assuming you have chosen to run the default ports you will need to open them in your router and default ports mean that you cannot play your server from the same computer.

If you have chosen your own ports then you will need to open these in your router but this time using custom ports means you can play your server from the same computer.

7) To see which ports you need to open you can run these commands from the server CLI

authport
updateport
lobbyport
gameport

Not specifying ports in the default.cfg uses the following default ports...
8766
3658
27015
27016

So we need to do the following in the port opening sections on the router

updateport = 27016 | UDP | YES
lobbyport = 27010 | TCP | YES
gameport = 3658 | UDP | YES

8) You will need to know your servers local IP address (LAN IP) and to find that out you need to open up a cmd from the start menu and then in the command prompt type

ipconfig /all

you are looking for your ipv4 address and it usually starts with something like 192.168.xxx.xxx
mine on a belkin router is 192.168.2.xxx
on a ZTE router it will be 192.168.200.xxx
on a netgear router it will be 192.168.1.xxx
on a dlink router it will be 192.168.0.xxx
etc
etc

Now you have found your avp servers lan ip address you need to put that somewhere in the routers port opening screen in step 7

9) Once you have done your router in steps 7 and 8 you can fire up your server again using the steam tools avp dedi option and you should see all the usual again in the avp server CLI screen.
This time though, go to Steam Client and at top left click on VIEW then Servers and filter it to just the Aliens vs. Predator servers.
You should see your server up and running and ready for others to find and join!

10) Once you start banning people you can find the list in this file:
C:\Program Files (x86)\Steam\steamapps\common\Aliens vs Predator Dedicated Server\logfiles\dedicated_console.txt

There are some useful documents and information provided by the devs that can assist in setting up dedicated servers.

Here is the main content for easy reference...

DedicatedServerReadme.txt
DedicatedServerCmdRef.pdf

Aliens vs Predator
Dedicated Server BETA
=====================

Table of Contents

1. Disclaimer
2. System Requirements
3. Quickstart Guide
4. Commands And Configuration Files
5. Ports
6. Banning Players
7. Known Issues
8. Update History
9. Technical Support

------------------------------------------------
1. Disclaimer
------------------------------------------------

This is a beta release of the Aliens vs Predator dedicated server and may not
yet be fully functional or stable in all circumstances.

Sega will not be held responsible for the risks connected with lost profit,
damage to property, lost data, loss of goodwill, console, computer or
handheld device failure, errors and lost business or other information as a
result of possession, use or malfunction of the Game Software or set up of
any dedicated server, even if Sega has been advised of the possibility of
such loss.

Sega will not be held liable for any damage, injury or loss if caused as a
result of your negligence, accident or misuse, or if the Game Software and/or
dedicated server has been modified in any manner (not by Sega) after it has
been bought.

Sega's liability shall not exceed the actual price paid for the Game Software.

Sega does not seek to exclude or limit its liability for any death or
personal injury arising from its negligence.

------------------------------------------------
2. System Requirements
------------------------------------------------

As an absolute minimum you must have the following UPSTREAM bandwidth
available to run a dedicated server:

8 player games: 0.5 Mbit
18 player games: 1 Mbit

However, we would recommend the following UPSTREAM bandwidth:

8 player games: 1 Mbit
18 player games: 2 Mbit

We also recommend for best performance that you run the server using a
publically accessible IP.

To host the server you should use a computer with the following
specification or better:

Operating System: Windows XP / Vista / 7
Processor: Intel® Core 2 Duo E6400 or equivalent processor
Memory: 2 GB System RAM (XP) / 3 GB System RAM (Vista / 7)
Hard Drive: 16 GB free space

Note: The game's performance may differ according to your computer's hardware
and/or video card. Computers with high-performance hardware will provide the
best game performance.

------------------------------------------------
3. Quickstart Guide
------------------------------------------------

i) Launch the dedicated server application

ii) Add a map to the map rotation, for example:

> addmap Jungle DM

iii) Start the server:

> host

------------------------------------------------
4. Commands And Configuration Files
------------------------------------------------

Please see the separate DedicatedServerCmdRef.pdf document for details of all
the commands available on the dedicated server.

You can use configuration files in order to execute a particular sequence of
commands, either on demand or at server start up. By default the server will
look for a configuration file called "default.cfg" and execute the commands
in that. You can use these configuration files for setting up map rotations,
game rules, etc.

If you wish to execute a different configuration file at start up then you
can use the "-exec" command line option to do so. For example:

AvP_CLI.exe -exec other.cfg

Note that the server will still attempt to run commands from "default.cfg"
in addition. It is however fine for that file to be empty or absent.

Advanced users may want to specify a particular IP address to bind to. This
can be done by adding -IP=<x.x.x.x> on the command line, e.g.

AvP_CLI.exe -IP=192.168.0.1 -exec other.cfg

------------------------------------------------
5. Ports
------------------------------------------------

The following ports are used by AvP and can be set on the dedicated server.
If you wish to run multiple server instances on a single machine then, after
ensuring that the machine's specification is up to the task, you will also
need to specify different ports for all of the below for each instance. The
easiest way of doing this will be to setup a different configuration file for
each server containing this information and also things like the server name.

Note: You must set the ports to be used before the server has started hosting
(i.e. before the 'host' command is invoked).

Description Protocol Command Open*

Steam authorisation port UDP authport NO
Steam master server updater port UDP updateport YES
Lobby data port TCP lobbyport YES
Game data port UDP gameport YES

* This field indicates that the port should be open to incoming traffic. If
the dedicated server is behind a router and/or firewall the port will need to
be added to the firewall exemptions and/or forwarded on the router

------------------------------------------------
6. Banning Players
------------------------------------------------

Banned players are added to a list which is stored on the dedicated server, a
player must be actively playing on the server to be banned. To remove a
player from the server, or ban them, perform the following steps:

i) Find the player index. Use the 'listplayers' command to display a list of
the active players and note the index of the relevant player. This is the
number to the left of their name.

ii) Kick or ban the player. Remove the player from the server with the 'kick'
command, or remove and ban them from the server with the 'kickban' command.
Pass the index of the player to these commands.

Note: When players leave and join the server, the index of each player may
change. You should ensure this does not happen between listing players and
using 'kick' or 'kickban'

------------------------------------------------
7. Known Issues
------------------------------------------------

i) Changing the game rules while a game is in progress is not recommended. If
possible ensure that all rules such as time and score limits, friendly fire,
species balancing etc are set before executing the host command. Changing these
once players have joined the server may cause problems such as clients not being
made aware of the new settings, or new settings appearing to have taken effect
but not actually doing so until the next round.

ii) If you don't set the species ratios the default values are used but the
server console commands report them all as -1.

------------------------------------------------
8. Update History
------------------------------------------------

i) Core version - 2.17 (first beta release)

First public version.

ii) Core version - 2.18 (second beta release)

New features:

Added new console commands "maxplayers" and "ip".
Improved "listplayers" console command.
Server info view inside Steam client includes player details.

Bugs fixed:

Fix crash that happened if connection to Steam was lost.
Removed some unused console commands from server console.
Command-line arguments are now checked case-insensitively.

iii) Core version - 2.19 (third beta release)

New features:

Improvements to the networking code used in dedicated server games to
increase stability and reduce pings.

Dedicated server no longer needs the Steam client to be running.

Dedicated server can use DLC maps.

New console commands for dedicated server for friendly fire, team balancing
and species balancing options.

New console command to set a Message of the Day.

When players join a dedicated server on which a round is in-progress they
now have a limited time to choose a species/team and skin before entering
the game.

Balance tweaks for predator weapons: Discs are now never fatal (if the target
has 100% health) unless they get a headshot, and Plasma Caster light bolts
have significantly reduced radial impulses to increase the number of direct
hits before knockdown. Both changes affect multiplayer only.

Improved feedback and output for various console commands.

Improved server console output when players disconnect.

Improved server console output when there are problems starting the server.

Additional server console output about the Steam connection.

Made the ban list file have the server’s port number appended so multiple
instances on the same hardware are independent.

Bugs fixed:

Fixed one cause of clients thinking the host had disconnected at the end of
a game which actually ended normally.

Fixed predators being able to cancel other players’ Plasma Caster Lock-on.

Setting the Autostarttime to "0" now correctly turns this feature off, rather
than attempting to instantly start the match upon players returning to the lobby.

Fixed an issue where dedicated servers left idle for an extended period of time
would result in the first match played having the clients "running around
without their bodies attached".

Prevent "Adding Master Server" console output looking corrupted.

Fixed team selection not working for the first map hosted on a dedicated server.


Additional notes:

Due to some improvements to the networking code, the new server and client are
not compatible with the old versions. Clients who have not yet restarted and
updated their game will not see updated servers in the in-game browser and
conversely, any servers that have not been updated will no longer be visible
in the in-game list for clients who have applied the update. Both new and old
servers will be visible in the Steam Client server list but players will see an
"Incompatible Version" error message if they attempt to connect to server which
has not been updated.

iV) Core version - 2.20 (fourth beta release)

Bugs fixed:

Fixed "Ghost players" being created on a server if the Steam backend could not be
reached for authentication when someone connected. These appeared in the player
counts when browsing servers, and in the server details player list when viewing
servers in the Steam client server list.


------------------------------------------------
9. Technical Support
------------------------------------------------

If you need further technical assistance after reading this ReadMe file
and the game manual, please do not hesitate to contact us using any of the
methods listed below.

When contacting us, please be sure to provide us with as much information
as possible. Make sure to note the exact type of hardware that you are
using in your system, including: your sound card, CD/DVD drive, amount
of RAM present, speed and manufacturer of your processor. Also, make sure
to include the title and version of the game, and a detailed description of
the problem.

It will also help if you prepare by creating a "DXDiag" diagnostic file in
Windows before you call us. To do this, simply follow these instructions:

i) Click on Start
ii) Click on Run
iii) Type "dxdiag"
iv) Click on OK
v) Click on the "Save All Information" button and save the file

When you call our Technical Support line either have this file open or have
a printed copy. If you send an e-mail query you may attach the file to the
e-mail.

Technical Support Contact Details (Europe):

info@segahelp.com
www.sega-europe.com

Technical Support Contact Details (North America):

www.sega.com/support

http://www.yougetsignal.com/tools/open-ports/

http://portforward.com/english/routers/port_forwarding/Belkin/F7D4401v1/Aliens_vs_Predator.htm

Here's some good stuff to know about running the server...

authport = 8766 | UDP | NO
updateport = 27016 | UDP | YES
lobbyport = 27010 | TCP | YES
gameport = 3658 | UDP | YES

Not specifying ports uses the following ports...
8766
3658
27015
27016


Default ports used gives this line at the end of the server CLI when the server starts...
Server listening on <yourWANIP>:27010
So this means that the default port running is 27010
This is good to know so that we can check using the portchekcer website to see if that port is open or not once our server is running.

Typing ? at the CLI gives us help.
How to use the console:
Type 'listcmds' for a list of all available commands.
Type 'listcmds <prefix>' for a list of commands beginning with <prefix>.
Type 'help <command>' or '? <command>' for help with a specific command.
Type '<command> [<parameter>]' to execute a command.
Type 'listvars' for a list of all available variables.
Type 'listvars <prefix>' for a list of variables beginning with <prefix>.
Type '<var name>' to view the value of a variable.
Type '<var name> <value>' to set the value of a variable.


Typing listcmds gives us all available commands
Available console commands:
?
AddMap
AlienRatio
AuthPort
AutoStartOnAllReady
AutoStartTime
Clear
ClearMapRotation
ClearPassword
EndGame
Exec
FriendlyFire
GamePort
Help
Host
IP
Kick
KickBan
ListBans
ListCmds
ListMapRotation
ListMaps
ListPlayers
ListVars
LobbyPort
MapRotationIndex
MarineRatio
MaxPlayers
MOTD
Password
PredatorRatio
Quit
Rcon
RemoveMap
say
ScoreLimit
ServerName
SpeciesBalancing
StartGame
TeamBalancing
TimeLimit
Unban
UpdatePort

// Wellen1981's Aliens vs. Predator Test Server Config

servername "Wellen1981 Test Server" // Server Name
maxplayers 6 // Set the maximum number of players allowed in the server
motd "If it bleeds, we can configure it!" // Display a message to players when they connect to your server

// Set your ports, replace xx with any two numbers, ports must be unique for each server you run on a machine. Delete the "270xx" to leave the ports at their default values.
authport
gameport
lobbyport
updateport

rconpassword WELLENTEST

// Jungle = map name, DM = game type, tl = time limit, and sl = score limit.

addmap Jungle PH tl=25 sl=30
addmap Ruins PH tl=25 sl=30
addmap Temple PH tl=25 sl=30
addmap Gateway PH tl=25 sl=30
addmap Refinery PH tl=25 sl=30

// Set species ratios: Given in this config, for each 1 Preador there can be 2 Marines, For each 1 Predator there can be 3 aliens and so forth.

predatorratio 1 // Any Value 1-4, relative to other species
marineratio 2 // Any Value 1-4, relative to other species
alienratio 3

// Set auto-balancing and friendly fire. 0 = False, 1 = True

speciesbalancing 1 // Enable or Disable auto-balancing for species
teambalancing 1 // Enable or Disable auto-team balancing
friendlyfire 1 // Enable or Disable Friendly Fire

autostartonallready 1 // Auto-Start matches when all players are ready, 0 = False, 1 = True
autostarttime 60 // Lobby Auto-Start Timer (In Seconds)
host // Start Hosting the Server, server will not show up in any list without this command!

//End configuration

You could just add the LAN IP of your server to your router's DMZ but it is a very bad idea!

Instead here's how to open the specific ports needed for your server.

I am using a Belkin router so the headings may be slightly different however, the numbers will be the same if you havent picked custom ports in your default.cfg file...

I log into my Belkin router then I go to the Firewall Section.
In here I go to the Virtual Servers page and fill in the following...

The server is up and running, can be found in the Steam Servers list, however for some reason trying the website to see if the ports are open still results in it showing closed.

All I can think is that this is due to the website checking from a different port possibly (maybe just simply port 80?).

I hope this guide is useful and any comments/feedback/suggestions just post below and I will do my best to respond or if you feel something is missing from the guide or needs clarifying let me know and I will add it or make it clearer.

Cheers and stay frosty!