'''Discord''' is used in the FlightGear community as an alternative to [[Mumble]], [[TeamSpeak]], [[FGCom]] or [[Ventrilo]].

Discord is a free voice and chat software that can be downloaded as an app or used in a browser.

== Invite links ==
{{note|1=Its advised that you create a permanent account, instead of creating guest accounts as some people create duplicate accounts which clogs up the member logs and makes it more difficult to @mention people.}}

Furthermore many other FlightGear servers exist that you may need an personal invite to join. The easiest way to find them is to go to the FlightGear server and ask or ask in forums.

=== Communities ===

{| class=wikitable
! Topic !! Invite link
|-
| FlightGear
| https://discord.gg/rzuV2DR
|-
| FlightGear Australia (Scenery Development & Community)
| https://discord.gg/JzTEXsZ
|-
| FlightGear Italia (ITA Mercenaries)
| https://discord.gg/5RzyXRf
|-
| FlightGear FDM School
| https://discord.gg/Uyrtsar
|-
| FlightGear Air Race League
| https://discord.gg/HCAuU9D
|-
| FlightGear Virtual Alliance
| https://discord.gg/VqzTG2N
|-
| FG Events
| https://discord.gg/GY4N6Cu
|-
| FG FDM School
| https://discord.gg/U5KXyMU
|-
| Operation Red Flag military FG community (OPRF)
| https://discord.gg/ptVapkE
|-
| Combined Joint Task Force 50 (OPRF event planning/hosting and more)
| https://discord.gg/2nxjb6y
|-
| Warbirds, WWII-era aircraft
| https://discord.gg/yJaP5Wn
|-
| FlightGear Republic, A friendly community about FlightGear.
| https://discord.gg/sBJy46Uq7z
|}

=== Aircraft-specific ===
{| class=wikitable
! Aircraft !! Invite link
|-
| Aermacchi MB-339
| https://discord.gg/vNZ5ZPv
|-
| Airbus [[Airbus A320 Family|A320]] & A330 Development
| https://discord.gg/7kzg9Te
|-
| Airbus A350 Development
| https://discord.gg/vK5f2s6
|-
| LincolnWorks (747 and A380)
| https://discord.gg/2DMVpnJ
|-
| F-111 Aardvark
| https://discord.gg/DSrSbmx
|-
| [[General Dynamics F-16 Fighting Falcon]]
| https://discord.gg/8RcYnjA
|-
| MD-11 and Autoflight by Octal
| https://discord.gg/gxAhC3j
|-
| [[Mikoyan-Gurevich MiG-21bis]]
| https://discord.gg/bs8xyz3
|-
| [[Mirage 2000]]
| https://discord.gg/xZ3r2KR
|-
| Panavia Tornado
| https://discord.gg/26rvkr2
|-
| [[Saab 37 Viggen]]
| https://discord.gg/RJTwS9a
|-
| SEPECAT Jaguar
| https://discord.gg/G5q5XYN
|}

== External links ==
* https://discord.com/ Official website

[[de:Discord]]

[[Category:Software]]
[[Category:Community]]
[[Category:Air Traffic Control]]

Howto:Multiplayer

2019-02-11T19:52:44Z

Megaf: /* Servers */

The '''multiplayer''' feature of [[FlightGear]] makes it possible to see other pilots and vice-versa. This makes it possible to fly in formation, perform [[mid-air refueling]] with tankers controlled by real people or contact real [[air traffic control|air traffic controllers]] to ask for guidance.

Multiplayer may cause extreme [[troubleshooting performance issues|framerate drops]] during the loading of aircraft models, especially heavy models such as the [[Boeing 777]] or [[Airbus A320neo]]. It is suggested to fly in locations other than the default [[San Francisco International Airport]], as there are often lots of pilots in the area who are often new, and do not follow ATC, or respect traffic.

== Notes ==
* Callsigns can be a maximum of seven characters.
* You might want to check the [[#Known issues|Known issues]] section.

== Connecting to Multiplayer ==
=== Built-in launcher and in-sim dialog ===
[[File:Multiplayer settings dialog.jpg|thumb|Multiplayer settings dialog]]
The easiest way to get online is to use the [[FlightGear Qt launcher|built-in launcher]] or the in-sim Multiplayer dialog. All you need to do is enter a callsign and select a server from the menu. Press Connect to go online.

=== Using FGRun ===
==== From the main page ====
[[File:Multiplayer.jpg|thumb|Multiplayer settings in [[FGRun]]]]
# Select your [[aircraft]] and starting airport as normal in [[FGRun]].
# On the last screen, tick the "Multiplayer" box. Also make sure that the "AI models" box is checked or you will not be able to see the other pilots' aircraft.
# Enter the …
#* '''Callsign''' of your choice.
#* '''Hostname:''' Enter <code>mpserverXX.flightgear.org</code> (with <code>XX</code> being the [[#Servers|server number]]).
#* '''In/Out:''' Set both ports to 5000.
# Click {{button|Run}} to start FlightGear.

To confirm that it's working, you can go to the multiplayer map at http://mpmap02.flightgear.org/ (in Hong Kong). Once FlightGear has started, you will notice chat messages that say "Hello" indicating pilots that are online. They will also pop up when a pilot joins the MP network. You can change this message by editing this line in <tt>''[http://sourceforge.net/p/flightgear/fgdata/ci/next/tree/preferences.xml#l763 $FG_ROOT/preferences.xml]''</tt>:
<syntaxhighlight lang="xml">
<chat type="string" preserve="y">Hello</chat>
</syntaxhighlight>
You may wish to use a different server, especially one closer to you.

==== From Network Settings ====
[[File:FGRun Advanced dialog - Network.png|thumb|The <tt>Network</tt> tab of the Advanced Options dialog in [[FGRun]] (in [[Changelog 3.2|FlightGear 3.2.0]]).]]
You can also change multiplayer settings in the <tt>Network</tt> tab of FGRun's Advanced Options.

# On the last page, click {{button|Advanced}}.
# Click <tt>Network</tt> in the left column.
# In the <tt>Multiplayer Options</tt> area …
#* Type your desired callsign into the box.
#* Set the parameters for the two other boxes; see [[#Using multiplayer from the command line|below]] for correct syntax.
#* Click {{button|OK}}, then run FlightGear.

=== Using multiplayer from the command line ===
When running FlightGear from the [[command line]], you can specify multiplayer settings. The two arguments are as follows:
<syntaxhighlight lang="bash">
--multiplay=direction,10,ip.address,port
--callsign=anything
</syntaxhighlight>

Obviously, <code>--callsign</code> can be anything you wish but it must be limited to 7 (seven) characters in length counting any dashes. If your callsign is too long, it will be cut off in the various displays where it is shown. Generally speaking, callsigns are of the form X-XXXXX. Check [https://fgtracker.ml/ this page] to see whether your callsign is already in use or not. Do not pick a callsign that is already used, as that will create problems! Please don't leave your callsign as "CALLSIG".

There are four arguments to <code>--multiplay</code>:
; direction
: Either <code>in</code> or <code>out</code>. <code>in</code> tells FlightGear to listen to packets of data coming in through the specified '''port'''. <code>out</code> tells FlightGear to send data out through the '''port'''.

; ip.address
: IP address of network interface being used by FlightGear. If left blank, FlightGear will listen to all network interfaces. If '''direction''' is set to <code>in</code>, FlightGear will listen to ''only'' this IP address.

; port
: Port that data is either being sent or received through. Usually set to <code>5000</code> and above.

== Advanced usage of multiplayer ==
=== Local setup for testing ===
It is possible to set up a local multiplayer network between two FlightGear instances ''without'' using a [[FGMS|multiplayer server]]. All you need to do is map each I/O port of one instance to the corresponding port(s) of the other instance:

{{Note|
{{FGCquote
|A socket connection requires not only an IP address, but also a port number for each side of the link - imagine a port number like a "mailbox" sitting at the address. This mailbox is used by the communicating processes to send out and receive "messages". Different processes (even when possibly identical programs) will need to use different port numbers when running. Because open ports ({{=}}mailboxes) cannot be shared.
Thus, you need to modify the client-side port settings for each additional instance that you are running on the same machine, and map the output port of one instance to the input port of the other instance (and vice versa).
|{{cite web |url=http://forum.flightgear.org/viewtopic.php?p=83068#p83068
|title=<nowiki>Re: 2 FGFS instances / 1 win7 running same time with MP?</nowiki>
|author=<nowiki>Hooray</nowiki>
|date=<nowiki>Thu Jun 10</nowiki>
}}
}}
}}

Command line parameters for the first instance:
<syntaxhighlight lang="bash">
--multiplay=out,10,127.0.0.1,5000 --multiplay=in,10,127.0.0.1,5001 --callsign=Test1
</syntaxhighlight>

Command line parameters for the second instance:
<syntaxhighlight lang="bash">
--multiplay=out,10,127.0.0.1,5001 --multiplay=in,10,127.0.0.1,5000 --callsign=Test2
</syntaxhighlight>

You can use this kind of setup to test multiplayer related features or troubleshoot multiplayer related bug reports that may be otherwise hard to reproduce over MP. As you can't access the configuration of other people's FlightGear, this technique allows you to have complete control over FlightGear's settings.

[[File:Direct-p2p-multiplayer-setup.png|800px|Screenshot demonstrating a "peer-to-peer" setup between two FlightGear instances running on the same machine via localhost (127.0.0.1) without any multiplayer server.]]

You can add an arbitrary number of channels to mirror your flight onto other servers, e.g. to a private fgms (FlightGear Multiplayer Server) using
<syntaxhighlight lang="bash">
--multiplay=out,10,my.private.server.ip,5000
</syntaxhighlight>

Additionally, the <code>in</code> argument above tells FG to listen '''only''' on the loopback/local interface - it will not receive packets arriving on the other network interface(s). If you want to also bind to other interfaces, just omit the IP address by using
<syntaxhighlight lang="bash">
--multiplay=in,10,,5000
</syntaxhighlight>

Check [https://fgtracker.ml/ this page] to see whether your callsign is already in use or not. Do not pick a callsign that is already used, as that will create problems!

==== Now, going more slowly for those who are completely lost... ====
{{Note|This section may contain out of date or inaccurate information.}}
This section ''ought'' to be unnecessary now with recent versions of the FG server. If you have problems though, it won't hurt to follow through.

First of all, you need to know the IP address of the network interface you'll be using for multiplayer FG.

If your Internet connection is via an ADSL modem that plugs directly into your computer, you should be able to find your IP address by visiting http://www.whatismyip.com.
{{Note|Your {{Abbr|ISP|Internet Service Provider}} might not give you the same IP address each time.}}

If your connection is via an Ethernet connector or by a wireless link.

* '''Linux:''' Log in as root and run <code>ifconfig</code> in the terminal. In the text that is returned, you should to look for an interface name such as <code>eth0</code> or <code>wlan0</code>. Finally, look in the text below the interface name for <code>inet addr:ip.address</code>. For example, this should read something like <code>inet addr:192.168.0.150</code>.
* '''Windows:'''
** '''Windows XP or later:''' Start Command Prompt and <code>ipconfig</code> into the terminal. Write the IP address down.
** '''Windows 98''', click start, run, and type "winipcfg" to get information about your IP address.

Now, all that remains is to configure your router to forward UDP port 5000 to the IP address you've just found. This is not something that can be described in step-by-step detail, because each manufacturer's configuration interfaces differ greatly. Some tips are given here – if you get stuck, ask nicely on the [[FlightGear IRC channel]] for help (details on the FlightGear website).

You should know how to log on to your router's configuration page, usually via a web browser. You are looking for settings pertaining to "port forwarding," "virtual server," "Forwarding Rules," or similar. When you have found the relevant settings, you need to add a rule that forwards port 5000 to the IP address you discovered earlier. If there is a choice given, ensure it is UDP ports that are forwarded. If there is no choice, you may assume that both TCP and UDP are being forwarded. Save your configuration, and most routers will probably then need to be rebooted to apply the changes.

{{Note|BSD users: If you are using a ADSL modem, you might have to put the port forward command into the ppp.conf file rather than firewall. This is because the firewall script will only run each time the machine is booted rather than the ppp line coming back online.}}

Finally, start FG using the command line given right at the start (if you're using the Windows launcher you will find entry boxes for Multiplayer arguments – insert the relevant details there). You will end up with something like this:
<syntaxhighlight lang="bash" enclose="div">
<other arguments> --callsign=test --multiplay=in,10,192.168.0.2,5000 --multiplay=out,10,mpserver05.flightgear.org,5000 --airport=KSFO --runway=28R --aircraft=hunter
</syntaxhighlight>

Choose your own callsign, but check [https://fgtracker.ml/ this page] first to see whether your desired callsign is already in use or not. Do not pick a callsign that is already used, as that will create problems!

Once you have started FG, you should, if others are flying, see messages in the terminal from which FG was started, similar to the following;

Initialising john51a using 'Aircraft/ufo/Models/ufo.xml'
FGMultiplayRxMgr::ProcessRxData - Add new player. IP: 10.0.0.36,
Call: john51a,model: Aircraft/ufo/Models/ufo.xml

You MUST give your local, behind-the-router IP address for multiplayer to work. Trust me on this one!

You should check that your firewall is not causing problems - either turn it off ''temporarily'' or add an exception to allow incoming connections on port 5000.

If it's still just not working for you, ask nicely on the [[FlightGear IRC channel|IRC channel]] or the [http://forum.flightgear.org/ forum] and someone should be able to assist.

=== Multiple connections per computer ===
It is possible to run multiple FlightGear instances on a single computer and connect them all to the multiplayer network. However, this requires some extras to keep in mind:
# Both instances use the same <code>out</code> port.
# One instance uses <code>in</code> port <code>5001</code>, the other port <code>5002</code>.
# Both instances have unique callsigns.

=== Optional collision detection in multiplayer ===

A patch has been added to FlightGear (since Version 3.5) to allow optional collision detection in multiplayer. To enable collision detection, start FlightGear with:

<syntaxhighlight>
--prop:bool:/sim/multiplay/hot=true
</syntaxhighlight>

Those who are able to patch FGData themselves, can download [http://sourceforge.net/p/flightgear/mailman/attachment/CAHs0wcrEwYZvXTddcUaH0ZMfmVNvEWRap8MXOrEoKybUDO58sQ%40mail.gmail.com/3/ mp-hot-fgdata.patch], which adds a checkbox to the Multiplayer Settings dialog to enable or disable the collision detection at runtime.

== Multiplayer chat ==
{{Main article|Chat Menu}}

To chat with other pilots, go to the <tt>Multiplayer</tt> menu and select <tt>Chat Menu</tt> at the bottom of the menu. Note that the other pilots may not have their chat box open nor chat messages enabled, so they may not see your messages.

The shortcut for chatting is {{Key press|<nowiki>-</nowiki>}} (hyphen). This will bring up some text in the upper-left of the FlightGear window. By pressing the corresponding number keys, you can send pre-made messages. Pressing {{Key press|1}} will let you type in a custom message, which you can send by pressing enter. By default, other people's messages are displayed at the top of FlightGear's window for a few seconds, but it will appear for a much longer time in the window at <tt>Network > Chat</tt>. So if you think you have missed anything, go check there.

== Dealing with abusive behavior ==
Should you become victim of abusive or annoying behavior by any pilot, you have option to ignore him or her. To activate the ignore function open the <tt>Multiplayer > Pilot list</tt> dialog and click the <tt>ignore</tt> button next to the pilot's callsign. This will prevent chat messages from the ignored pilot appearing and prevent his aircraft from appearing (unless you are using FlightGear v2.2 or older).

== Multiplayer map ==
[[File:MP_Server.jpg|thumb|300px|[[MPMap]] screenshot]]
{{Main article|MPMap}}

There is a very nice online map which displays the location of online pilots at [http://mpmap02.flightgear.org mpmap02]. You will also find this useful to check that you are successfully connecting to the server, as well as looking up navaids, waypoints, airports, frequencies, weather, and more!

== Servers ==
The multiplayer servers are interconnected. With few exceptions you ''do not'' need to connect to a specific server in order to see other pilots who are on that server. For best performance, you should connect to the server that is either geographically closest to you, has the lowest latency (ping time), or is the least busy.
{{tip|Use [http://mpmap01.flightgear.org/mpstatus/ this link] to check if the MP servers are online. Page is automatically generated. The [[#In-sim Dialog|in-sim dialog]] will only display servers that are available.}}

{| class="wikitable sortable"
! Server address
! Status
! Location
! Tracked (by [http://fgtracker.ml fgtracker.ml] unless otherwise specified)
! Maintainer
! Maintainer's [[IRC]] name
! Maintainer's [http://flightgear.org/forums forum] name
! Comments
|-
| mpserver01.flightgear.org
| {{yes|Up}}
| Germany
| {{yes}}
| Oliver Schröder
| os
| {{N/a}}
| {{N/a|None}}
|-
| mpserver02.flightgear.org
| {{yes|Up}}
| Los Angeles, USA
| {{N/a}}
| Lloyd Stevens
| ls4680
| ls4680
| {{N/a|None}}
|-
| mpserver03.flightgear.org
| {{yes|Up}}
| Germany
| {{yes}}
| Hergen
| {{N/a}}
| {{N/a}}
| [https://mpserver03.flightgear.org mpserver03.flightgear.org]
|-
| mpserver04.flightgear.org
| {{yes|Up}}
| UK
| {{no}}
| Jon Stockill
| Nav
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=738 JonS]
| {{N/a|None}}
|-
| mpserver05.flightgear.org
| {{no|Down}}
| Chicago, USA
| {{N/a}}
| Brant
| IonCannon218
| {{N/a}}
| {{N/a|None}}
|-
| mpserver06.flightgear.org
| {{no|Down}}
| Berlin, Germany
| {{N/a}}
| Sven Teichmann
| {{N/a}}
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=11839 D-SAMI]
| Unlimited traffic
|-
| mpserver07.flightgear.org
| {{no|Down}}
| Wisconsin, USA
| {{N/a}}
| Tom Betka
| TB
| {{N/a}}
| Offline
|-
| mpserver08.flightgear.org
| {{no|Down}}
| Frankfurt am Main, Germany
| {{N/a}}
| Roland
| Quix0r
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=7512 Quix0r]
| 10 TByte traffic, mostly short pings
|-
| mpserver09.flightgear.org
| {{no|Down}}
| Köln, Germany
| {{N/a}}
| Daniel Vigano
| Fauchi95
| {{N/a}}
| Offline
|-
| mpserver10.flightgear.org
| {{no|Down}}
| Montpellier, France
| {{N/a}}
| {{usr|Xiii|Alexis Bory}}
| xiii
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=884 xiii]
| {{N/a|None}}
|-
| mpserver11.flightgear.org
| {{no|Down}}
| Vilnius, Lithuania
| {{N/a}}
| Darius
| {{N/a}}
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=1122 ffg]
| {{N/a|None}}
|-
| mpserver12.org
| {{no}}
| Amsterdam, the Netherlands
| {{no}} ([http://mpserver12.org mpserver12.org])
| Rob
| evilslut
| {{N/a}}
| Formerly mpserver12.flightgear.org<ref>http://forum.flightgear.org/viewtopic.php?f=27&t=27453&start=60#p258435</ref>
|-
| mpserver13.flightgear.org
| {{yes|Up}}
| Beauvais, France
| {{N/a}}
| Charles Ingels
| charles
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=1592 cbz-026]
| {{N/a|None}}
|-
| mpserver14.flightgear.org
| {{yes|Up}}
| UK
| {{no}}
| Pete
| {{N/a}}
| {{N/a}}
| {{N/a|None}}
|-
| mpserver15.flightgear.org
| {{yes|Up}}
| North Point, Hong Kong
| {{yes}}
| Hazuki Amamiya
| Hazuki
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=8400 Hazuki]
| {{N/a|None}}
|-
| mpserver16.flightgear.org
| {{yes|Up}}
| Kansas City, Missouri, USA
| {{no}}
| Rob Dosogne
| truthsolo
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=9926 truthsolo]
| {{N/a|None}}
|-
| mpserver17.flightgear.org
| {{no|Down}}
| Cluj, Romania
| {{N/a}}
| Marius
| tuxum
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=11636 tuxum]
| Offline
|-
| mpserver18.flightgear.org
| {{no|Down}}
| Germany
| {{N/a}}
| {{N/a}}
| {{N/a}}
| {{N/a}}
| {{N/a}}
|-
| mpserver19.flightgear.org
| {{yes|Up}}
| London, UK
| {{yes}}
| Dr. R0ckso
| drr0ckso
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21111 drR0ckso]
| {{N/a|None}}
|-
| mpserver20.flightgear.org
| {{yes|Up}}
| South San Francisco, California, USA
| {{yes}}
| Marisa Giancarla
| marisag
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21604 marisag]
| {{N/a|None}}
|-
| mpserver21.flightgear.org
| {{yes|Up}}
| Tokyo, Japan
| {{yes}}
| Marisa Giancarla
| marisag
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21604 marisag]
| {{N/a|None}}
|-
| mpserver51.flightgear.org
| {{yes|Up}}
| Atlanta, Georgia, USA
| {{yes}}
| Dr. R0ckso
| drr0ckso
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21111 drR0ckso]
| Radio horizon is 414 miles
|-
| mpserver87.flightgear.org
| {{yes|Up}}
| Paris, France
| {{yes}}
| Megaf
| Megaf
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21017 Megaf]
| 2000 nmi Range and Radar Range.
|}

Geographic locations of the servers are also available at [http://goo.gl/maps/jBwUd Google Maps].

If you are interested in hosting your own multiplayer server, you may want to check out [[Howto: Set up a multiplayer server]].

== Known issues ==
=== Fibertel (Argentina) ===
In December 2014, it was reported that UDP connection through port 5000 was not possible for users whose ISP was {{Wikipedia|Fibertel}} (Argentina).

Fibertel Argentina apparently uses the port for setup purposes. "It should be open for the user but it might not be fully functional."

Port 5000 is a generic port, and neither FlightGear nor the {{Wikipedia|UPnP}} protocol are an "official" usage of the port.

A solution would be to spread the ports between the servers; e.g., mpserver01.flightgear.org → 5001, mpserver02.flightgear.org → 5002

See also the [http://forum.flightgear.org/viewtopic.php?f=27&t=24754 forum thread] and {{issue|1617}}.

== Related content ==
* [[FlightGear Multiplayer Server]]
* [[Howto: Set up a multiplayer server]]
* [[Multiplayer protocol]]
* [[Howto:Transmit_properties_over_MP]]

{{Appendix}}

[[Category:Multiplayer]]
[[Category:Howto|Multiplayer]]

[[de:Howto: Multiplayer]]
[[es:Howto: Multijugador]]
[[fr:Howto: Multijoueur]]
[[it:Come fare:Multiplayer]]
[[nl:Howto: Multiplayer]]
[[pl:Konfiguracja trybu multiplayer]]
[[pt:Tutorial de Multiplayer]]

Howto:Multiplayer

2018-08-12T02:45:35Z

Megaf: Added mpserver87. Still learning, be patient please.

The '''multiplayer''' feature of [[FlightGear]] makes it possible to see other pilots and vice-versa. This makes it possible to fly in formation, perform [[mid-air refueling]] with tankers controlled by real people or contact real [[air traffic control|air traffic controllers]] to ask for guidance.

Multiplayer may cause extreme [[troubleshooting performance issues|framerate drops]] during the loading of aircraft models, especially heavy models such as the [[Boeing 777]] or [[Airbus A320neo]]. It is suggested to fly in locations other than the default [[San Francisco International Airport]], as there are often lots of pilots in the area who are often new, and do not follow ATC, or respect traffic.

== Notes ==
* Callsigns can be a maximum of seven characters.
* You might want to check the [[#Known issues|Known issues]] section.

== Connecting to Multiplayer ==
=== Built-in launcher and in-sim dialog ===
[[File:Multiplayer settings dialog.jpg|thumb|Multiplayer settings dialog]]
The easiest way to get online is to use the [[FlightGear Qt launcher|built-in launcher]] or the in-sim Multiplayer dialog. All you need to do is enter a callsign and select a server from the menu. Press Connect to go online.

=== Using FGRun ===
==== From the main page ====
[[File:Multiplayer.jpg|thumb|Multiplayer settings in [[FGRun]]]]
# Select your [[aircraft]] and starting airport as normal in [[FGRun]].
# On the last screen, tick the "Multiplayer" box. Also make sure that the "AI models" box is checked or you will not be able to see the other pilots' aircraft.
# Enter the …
#* '''Callsign''' of your choice.
#* '''Hostname:''' Enter <code>mpserverXX.flightgear.org</code> (with <code>XX</code> being the [[#Servers|server number]]).
#* '''In/Out:''' Set both ports to 5000.
# Click {{button|Run}} to start FlightGear.

To confirm that it's working, you can go to the multiplayer map at http://mpmap02.flightgear.org/ (in Hong Kong). Once FlightGear has started, you will notice chat messages that say "Hello" indicating pilots that are online. They will also pop up when a pilot joins the MP network. You can change this message by editing this line in <tt>''[http://sourceforge.net/p/flightgear/fgdata/ci/next/tree/preferences.xml#l763 $FG_ROOT/preferences.xml]''</tt>:
<syntaxhighlight lang="xml">
<chat type="string" preserve="y">Hello</chat>
</syntaxhighlight>
You may wish to use a different server, especially one closer to you.

==== From Network Settings ====
[[File:FGRun Advanced dialog - Network.png|thumb|The <tt>Network</tt> tab of the Advanced Options dialog in [[FGRun]] (in [[Changelog 3.2|FlightGear 3.2.0]]).]]
You can also change multiplayer settings in the <tt>Network</tt> tab of FGRun's Advanced Options.

# On the last page, click {{button|Advanced}}.
# Click <tt>Network</tt> in the left column.
# In the <tt>Multiplayer Options</tt> area …
#* Type your desired callsign into the box.
#* Set the parameters for the two other boxes; see [[#Using multiplayer from the command line|below]] for correct syntax.
#* Click {{button|OK}}, then run FlightGear.

=== Using multiplayer from the command line ===
When running FlightGear from the [[command line]], you can specify multiplayer settings. The two arguments are as follows:
<syntaxhighlight lang="bash">
--multiplay=direction,10,ip.address,port
--callsign=anything
</syntaxhighlight>

Obviously, <code>--callsign</code> can be anything you wish. There are four arguments to <code>--multiplay</code>:
; direction
: Either <code>in</code> or <code>out</code>. <code>in</code> tells FlightGear to listen to packets of data coming in through the specified '''port'''. <code>out</code> tells FlightGear to send data out through the '''port'''.

; ip.address
: IP address of network interface being used by FlightGear. If left blank, FlightGear will listen to all network interfaces. If '''direction''' is set to <code>in</code>, FlightGear will listen to ''only'' this IP address.

; port
: Port that data is either being sent or received through. Usually set to <code>5000</code> and above.

== Advanced usage of multiplayer ==
=== Local setup for testing ===
It is possible to set up a local multiplayer network between two FlightGear instances ''without'' using a [[FGMS|multiplayer server]]. All you need to do is map each I/O port of one instance to the corresponding port(s) of the other instance:

{{Note|
{{FGCquote
|A socket connection requires not only an IP address, but also a port number for each side of the link - imagine a port number like a "mailbox" sitting at the address. This mailbox is used by the communicating processes to send out and receive "messages". Different processes (even when possibly identical programs) will need to use different port numbers when running. Because open ports ({{=}}mailboxes) cannot be shared.
Thus, you need to modify the client-side port settings for each additional instance that you are running on the same machine, and map the output port of one instance to the input port of the other instance (and vice versa).
|{{cite web |url=http://forum.flightgear.org/viewtopic.php?p=83068#p83068
|title=<nowiki>Re: 2 FGFS instances / 1 win7 running same time with MP?</nowiki>
|author=<nowiki>Hooray</nowiki>
|date=<nowiki>Thu Jun 10</nowiki>
}}
}}
}}

Command line parameters for the first instance:
<syntaxhighlight lang="bash">
--multiplay=out,10,127.0.0.1,5000 --multiplay=in,10,127.0.0.1,5001 --callsign=Test1
</syntaxhighlight>

Command line parameters for the second instance:
<syntaxhighlight lang="bash">
--multiplay=out,10,127.0.0.1,5001 --multiplay=in,10,127.0.0.1,5000 --callsign=Test2
</syntaxhighlight>

You can use this kind of setup to test multiplayer related features or troubleshoot multiplayer related bug reports that may be otherwise hard to reproduce over MP. As you can't access the configuration of other people's FlightGear, this technique allows you to have complete control over FlightGear's settings.

[[File:Direct-p2p-multiplayer-setup.png|800px|Screenshot demonstrating a "peer-to-peer" setup between two FlightGear instances running on the same machine via localhost (127.0.0.1) without any multiplayer server.]]

You can add an arbitrary number of channels to mirror your flight onto other servers, e.g. to a private fgms (FlightGear Multiplayer Server) using
<syntaxhighlight lang="bash">
--multiplay=out,10,my.private.server.ip,5000
</syntaxhighlight>

Additionally, the <code>in</code> argument above tells FG to listen '''only''' on the loopback/local interface - it will not receive packets arriving on the other network interface(s). If you want to also bind to other interfaces, just omit the IP address by using
<syntaxhighlight lang="bash">
--multiplay=in,10,,5000
</syntaxhighlight>

Check [https://fgtracker.ml/ this page] to see whether your callsign is already in use or not. Do not pick a callsign that is already used, as that will create problems!

==== Now, going more slowly for those who are completely lost... ====
{{Note|This section may contain out of date or inaccurate information.}}
This section ''ought'' to be unnecessary now with recent versions of the FG server. If you have problems though, it won't hurt to follow through.

First of all, you need to know the IP address of the network interface you'll be using for multiplayer FG.

If your Internet connection is via an ADSL modem that plugs directly into your computer, you should be able to find your IP address by visiting http://www.whatismyip.com.
{{Note|Your {{Abbr|ISP|Internet Service Provider}} might not give you the same IP address each time.}}

If your connection is via an Ethernet connector or by a wireless link.

* '''Linux:''' Log in as root and run <code>ifconfig</code> in the terminal. In the text that is returned, you should to look for an interface name such as <code>eth0</code> or <code>wlan0</code>. Finally, look in the text below the interface name for <code>inet addr:ip.address</code>. For example, this should read something like <code>inet addr:192.168.0.150</code>.
* '''Windows:'''
** '''Windows XP or later:''' Start Command Prompt and <code>ipconfig</code> into the terminal. Write the IP address down.
** '''Windows 98''', click start, run, and type "winipcfg" to get information about your IP address.

Now, all that remains is to configure your router to forward UDP port 5000 to the IP address you've just found. This is not something that can be described in step-by-step detail, because each manufacturer's configuration interfaces differ greatly. Some tips are given here – if you get stuck, ask nicely on the [[FlightGear IRC channel]] for help (details on the FlightGear website).

You should know how to log on to your router's configuration page, usually via a web browser. You are looking for settings pertaining to "port forwarding," "virtual server," "Forwarding Rules," or similar. When you have found the relevant settings, you need to add a rule that forwards port 5000 to the IP address you discovered earlier. If there is a choice given, ensure it is UDP ports that are forwarded. If there is no choice, you may assume that both TCP and UDP are being forwarded. Save your configuration, and most routers will probably then need to be rebooted to apply the changes.

{{Note|BSD users: If you are using a ADSL modem, you might have to put the port forward command into the ppp.conf file rather than firewall. This is because the firewall script will only run each time the machine is booted rather than the ppp line coming back online.}}

Finally, start FG using the command line given right at the start (if you're using the Windows launcher you will find entry boxes for Multiplayer arguments – insert the relevant details there). You will end up with something like this:
<syntaxhighlight lang="bash" enclose="div">
<other arguments> --callsign=test --multiplay=in,10,192.168.0.2,5000 --multiplay=out,10,mpserver05.flightgear.org,5000 --airport=KSFO --runway=28R --aircraft=hunter
</syntaxhighlight>

Choose your own callsign, but check [https://fgtracker.ml/ this page] first to see whether your desired callsign is already in use or not. Do not pick a callsign that is already used, as that will create problems!

Once you have started FG, you should, if others are flying, see messages in the terminal from which FG was started, similar to the following;

Initialising john51a using 'Aircraft/ufo/Models/ufo.xml'
FGMultiplayRxMgr::ProcessRxData - Add new player. IP: 10.0.0.36,
Call: john51a,model: Aircraft/ufo/Models/ufo.xml

You MUST give your local, behind-the-router IP address for multiplayer to work. Trust me on this one!

You should check that your firewall is not causing problems - either turn it off ''temporarily'' or add an exception to allow incoming connections on port 5000.

If it's still just not working for you, ask nicely on the [[FlightGear IRC channel|IRC channel]] or the [http://forum.flightgear.org/ forum] and someone should be able to assist.

=== Multiple connections per computer ===
It is possible to run multiple FlightGear instances on a single computer and connect them all to the multiplayer network. However, this requires some extras to keep in mind:
# Both instances use the same <code>out</code> port.
# One instance uses <code>in</code> port <code>5001</code>, the other port <code>5002</code>.
# Both instances have unique callsigns.

=== Optional collision detection in multiplayer ===

A patch has been added to FlightGear (since Version 3.5) to allow optional collision detection in multiplayer. To enable collision detection, start FlightGear with:

<syntaxhighlight>
--prop:bool:/sim/multiplay/hot=true
</syntaxhighlight>

Those who are able to patch FGData themselves, can download [http://sourceforge.net/p/flightgear/mailman/attachment/CAHs0wcrEwYZvXTddcUaH0ZMfmVNvEWRap8MXOrEoKybUDO58sQ%40mail.gmail.com/3/ mp-hot-fgdata.patch], which adds a checkbox to the Multiplayer Settings dialog to enable or disable the collision detection at runtime.

== Multiplayer chat ==
{{Main article|Chat Menu}}

To chat with other pilots, go to the <tt>Multiplayer</tt> menu and select <tt>Chat Menu</tt> at the bottom of the menu. Note that the other pilots may not have their chat box open nor chat messages enabled, so they may not see your messages.

The shortcut for chatting is {{Key press|<nowiki>-</nowiki>}} (hyphen). This will bring up some text in the upper-left of the FlightGear window. By pressing the corresponding number keys, you can send pre-made messages. Pressing {{Key press|1}} will let you type in a custom message, which you can send by pressing enter. By default, other people's messages are displayed at the top of FlightGear's window for a few seconds, but it will appear for a much longer time in the window at <tt>Network > Chat</tt>. So if you think you have missed anything, go check there.

== Dealing with abusive behavior ==
Should you become victim of abusive or annoying behavior by any pilot, you have option to ignore him or her. To activate the ignore function open the <tt>Multiplayer > Pilot list</tt> dialog and click the <tt>ignore</tt> button next to the pilot's callsign. This will prevent chat messages from the ignored pilot appearing and prevent his aircraft from appearing (unless you are using FlightGear v2.2 or older).

== Multiplayer map ==
[[File:MP_Server.jpg|thumb|300px|[[MPMap]] screenshot]]
{{Main article|MPMap}}

There is a very nice online map which displays the location of online pilots at [http://mpmap02.flightgear.org mpmap02]. You will also find this useful to check that you are successfully connecting to the server, as well as looking up navaids, waypoints, airports, frequencies, weather, and more!

== Servers ==
The multiplayer servers are interconnected. With few exceptions you ''do not'' need to connect to a specific server in order to see other pilots who are on that server. For best performance, you should connect to the server that is either geographically closest to you, has the lowest latency (ping time), or is the least busy.
{{tip|Use [http://mpmap01.flightgear.org/mpstatus/ this link] to check if the MP servers are online. Page is automatically generated. The [[#In-sim Dialog|in-sim dialog]] will only display servers that are available.}}

{| class="wikitable sortable"
! Server address
! Status
! Location
! Tracked (by [http://fgtracker.ml fgtracker.ml] unless otherwise specified)
! Maintainer
! Maintainer's [[IRC]] name
! Maintainer's [http://flightgear.org/forums forum] name
! Comments
|-
| mpserver01.flightgear.org
| {{yes|Up}}
| Germany
| {{yes}}
| Oliver Schröder
| os
| {{N/a}}
| {{N/a|None}}
|-
| mpserver02.flightgear.org
| {{yes|Up}}
| Los Angeles, USA
| {{N/a}}
| Lloyd Stevens
| ls4680
| ls4680
| {{N/a|None}}
|-
| mpserver03.flightgear.org
| {{yes|Up}}
| Germany
| {{yes}}
| Hergen
| {{N/a}}
| {{N/a}}
| [https://mpserver03.flightgear.org mpserver03.flightgear.org]
|-
| mpserver04.flightgear.org
| {{yes|Up}}
| UK
| {{no}}
| Jon Stockill
| Nav
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=738 JonS]
| {{N/a|None}}
|-
| mpserver05.flightgear.org
| {{no|Down}}
| Chicago, USA
| {{N/a}}
| Brant
| IonCannon218
| {{N/a}}
| {{N/a|None}}
|-
| mpserver06.flightgear.org
| {{no|Down}}
| Berlin, Germany
| {{N/a}}
| Sven Teichmann
| {{N/a}}
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=11839 D-SAMI]
| Unlimited traffic
|-
| mpserver07.flightgear.org
| {{no|Down}}
| Wisconsin, USA
| {{N/a}}
| Tom Betka
| TB
| {{N/a}}
| Offline
|-
| mpserver08.flightgear.org
| {{no|Down}}
| Frankfurt am Main, Germany
| {{N/a}}
| Roland
| Quix0r
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=7512 Quix0r]
| 10 TByte traffic, mostly short pings
|-
| mpserver09.flightgear.org
| {{no|Down}}
| Köln, Germany
| {{N/a}}
| Daniel Vigano
| Fauchi95
| {{N/a}}
| Offline
|-
| mpserver10.flightgear.org
| {{no|Down}}
| Montpellier, France
| {{N/a}}
| {{usr|Xiii|Alexis Bory}}
| xiii
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=884 xiii]
| {{N/a|None}}
|-
| mpserver11.flightgear.org
| {{no|Down}}
| Vilnius, Lithuania
| {{N/a}}
| Darius
| {{N/a}}
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=1122 ffg]
| {{N/a|None}}
|-
| mpserver12.org
| {{no}}
| Amsterdam, the Netherlands
| {{no}} ([http://mpserver12.org mpserver12.org])
| Rob
| evilslut
| {{N/a}}
| Formerly mpserver12.flightgear.org<ref>http://forum.flightgear.org/viewtopic.php?f=27&t=27453&start=60#p258435</ref>
|-
| mpserver13.flightgear.org
| {{yes|Up}}
| Beauvais, France
| {{N/a}}
| Charles Ingels
| charles
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=1592 cbz-026]
| {{N/a|None}}
|-
| mpserver14.flightgear.org
| {{yes|Up}}
| UK
| {{no}}
| Pete
| {{N/a}}
| {{N/a}}
| {{N/a|None}}
|-
| mpserver15.flightgear.org
| {{yes|Up}}
| North Point, Hong Kong
| {{yes}}
| Hazuki Amamiya
| Hazuki
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=8400 Hazuki]
| {{N/a|None}}
|-
| mpserver16.flightgear.org
| {{yes|Up}}
| Kansas City, Missouri, USA
| {{no}}
| Rob Dosogne
| truthsolo
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=9926 truthsolo]
| {{N/a|None}}
|-
| mpserver17.flightgear.org
| {{no|Down}}
| Cluj, Romania
| {{N/a}}
| Marius
| tuxum
| [http://forum.flightgear.org/memberlist.php?mode=viewprofile&u=11636 tuxum]
| Offline
|-
| mpserver18.flightgear.org
| {{no|Down}}
| Germany
| {{N/a}}
| {{N/a}}
| {{N/a}}
| {{N/a}}
| {{N/a}}
|-
| mpserver19.flightgear.org
| {{yes|Up}}
| London, UK
| {{yes}}
| Dr. R0ckso
| drr0ckso
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21111 drR0ckso]
| {{N/a|None}}
|-
| mpserver20.flightgear.org
| {{yes|Up}}
| South San Francisco, California, USA
| {{yes}}
| Marisa Giancarla
| marisag
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21604 marisag]
| {{N/a|None}}
|-
| mpserver21.flightgear.org
| {{yes|Up}}
| Tokyo, Japan
| {{yes}}
| Marisa Giancarla
| marisag
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21604 marisag]
| {{N/a|None}}
|-
| mpserver51.flightgear.org
| {{yes|Up}}
| Atlanta, Georgia, USA
| {{yes}}
| Dr. R0ckso
| drr0ckso
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21111 drR0ckso]
| Radio horizon is 414 miles
|-
| mpserver87.megaf.info
| {{yes|Up}}
| Paris, France
| {{yes}}
| Megaf
| Megaf
| [https://forum.flightgear.org/memberlist.php?mode=viewprofile&u=21017 Megaf]
| Not linked to others yet
|}

Geographic locations of the servers are also available at [http://goo.gl/maps/jBwUd Google Maps].

If you are interested in hosting your own multiplayer server, you may want to check out [[Howto: Set up a multiplayer server]].

== Known issues ==
=== Fibertel (Argentina) ===
In December 2014, it was reported that UDP connection through port 5000 was not possible for users whose ISP was {{Wikipedia|Fibertel}} (Argentina).

Fibertel Argentina apparently uses the port for setup purposes. "It should be open for the user but it might not be fully functional."

Port 5000 is a generic port, and neither FlightGear nor the {{Wikipedia|UPnP}} protocol are an "official" usage of the port.

A solution would be to spread the ports between the servers; e.g., mpserver01.flightgear.org → 5001, mpserver02.flightgear.org → 5002

See also the [http://forum.flightgear.org/viewtopic.php?f=27&t=24754 forum thread] and {{issue|1617}}.

== Related content ==
* [[FlightGear Multiplayer Server]]
* [[Howto: Set up a multiplayer server]]
* [[Multiplayer protocol]]
* [[Howto:Transmit_properties_over_MP]]

{{Appendix}}

[[Category:Multiplayer]]
[[Category:Howto|Multiplayer]]

[[de:Howto: Multiplayer]]
[[es:Howto: Multijugador]]
[[fr:Howto: Multijoueur]]
[[it:Come fare:Multiplayer]]
[[nl:Howto: Multiplayer]]
[[pl:Konfiguracja trybu multiplayer]]
[[pt:Tutorial de Multiplayer]]