I got the connetion failed at arma 2 but not on all servers, it is the same on Arma 3. I have noticed that my brother have a similar problem on black ops 2 xbox version where the NAT type says strict, even if i had opened the ports. So it is probably not game related.

Likewise with a Thomson, I cannot successfully connect to a match beyond the role assignment screen.

Get a new router, this is not armas fault, I had the same router in the past had a bunch of problems in all diffrent games (like WoW and BF3 for example). There is 2 solutions to the problem use a proxxy or get another router.

Having switched routers to a DLink, the problem no longer exists.

I wonder why one specific router can just mess things like that up. It is just wierd....

EDIT: Spelling

I too am getting this issue. My speculation is that it is NAT related, seeing I can join a server, or have my server joined by remote connect just fine.

Oh yeah, additional information: Server that cannot be connected to show up as "?" ping servers, when clicked and communicated with the ping cell is filled with 2500. Servers that are joinable are few and far in between but show up with a regular ping.

My pings show just fine and I'm still not able to connect. Other games work just fine including Arma II, THOMSON TG789vn. Ports have been forwarded etc. no effect.

going by the comments im also have this problem but it not thomson router i use it is Netopia Router

Your router may have some ports that are closed, preventing the game from properly connecting. Get a more video-game compliant router, like D-Links or anything that allows you to openly forward and edit ports.

My Thomson router was given to me by my internet provider, can i just change router like that or will i have problems with them?

I have a Thomson router and play Arma 3 online with no problems. However, I have had problems with Steam games before. I downloaded some custom files which fixed the problem. I have no idea whether or not this actually works with Arma 3 as well, but it's worth a try. Just google "Client dropped by server" and the top link (Steam Support) should be the one. Just follow the instructions in the green box. If anyone can confirm if this works or not, it would be much appreciated.

Im going to try it today, will be back with the evaluation later.
Thanks

Thomson routers are worthless for games.. I had problems with mine with basically every game.. and I mean everything from Terraria to Arma 3..

Solution: Change router! It's going to keep causing problems in the future as well!

Sooo.... i test it via Hamachi with some guys who have also a TG Router and it works well... but it doesn't work via Internet direct!

Have you tried enabling UPNP in the router?

Thomson routers are shit. Replace your router.

Please note that this problem is related to UDP flooding, which in most cases can't be disabled at ISP provided modems (which are usually Thomsom routers...)

My testcase:

• I have a Thomson tg789vn (from KPN, a Dutch ISP), and can't modify UDP flooding or other security settings
• I do not have an additional firewall (is disabled to test)
• checked with both UPnP on and off
• checked with both portforwarding enabled and disabled

When I host a server; nobody can join. Either with 'ping 2500', or just 'Connection Failed'.

When somebody else hosts the server (even dedicated); I can join when their firewall is disabled and UDP flooding is disabled, otherwise I can't join even when others can.

This problem is also present in ArmA2 (and I've seen the same problem with OPF, ArmA and TOH).

It's not an VR bug, but a case of crappy routers and their security measures...

I seems to have overcome a bit of the problem. I have a technicolor tg788vn.

I tested a bunch of configuration : firewall enabled/disabled, upnp, port fordwarding etc...

I have been able to join to a lot of server with this configuration :

• Upnp enabled
• Port forwarding 2302 -> 2309
• Firewall enabled (set to 'Standard')
• Add a rule to the firewall : accept ICMP packet from everywhere to everywhere (LAN/WAN)

I believe only the last rule might be relevant. Still weird though.

I am able to join to some server, ping seems fairly well to a bunch of servers now (I had several to none below 2500 before)

A last sad thing :
I tried to join to a server created by a friend (other people were able to join) but it didn't work for me (ping 2500)
I tried to create a server, nobody could join.

I don't know if the ICMP packet thing is really relevant, I will investigate more later. Maybe the UDP flooding rule was just nice yesterday... (post above)

Is there any 3rd party custom firmware for these routers? Like dd-wrt? If so, will probably solve all issues with these.

I had a thomson crapbox myself before.
My solution was to call my ISP and ask for them to bridge it so it only works as a modem and then use my own router.
solved all issues. As a modem it actually works rather well.

This worked on TG789nv which was the one i had.

You need Custom FW like i have than you can use PPPoE connection direct on PC and you dont have any problems ;-)
if anyone is from Austria i can send this FW for TG 789(VDSL generic relpppoe MU)

Correct. I have the same problem with my router.

Not Arma 3 related. Please check some official Thompson forum or any other router/modem related forums.
Closing