Can`t join players on Modern Warfare 3

[Swinzon]

My friend has a issue with Modern Warfare 3 on PC, he can`t join people and people can`t join him. He can join normal sessions.
Is there anyone that can help us out?
He have open the correct ports and NAT Type is open.

Thanks

[Leonard]

1. Is he using legit MW3 or technogods/alteriw? 
2. these are the ports for port forwarding of MW3, TCP = 3074, 27014-27050    UDP = 3074, 27000-27030 does he have these ports as well and does the IP address for these ports match his PC's IP address?
3. Has he allowed dedi servers in the menu?
4. has he disabled DLC by pressing F1 on the menu page where shows the NAT type?

[Swinzon]

4 minutes ago, Leonard said:

1. Is he using legit MW3 or technogods/alteriw? 
2. these are the ports for port forwarding of MW3, TCP = 3074, 27014-27050    UDP = 3074, 27000-27030 does he have these ports as well and does the IP address for these ports match his PC's IP address?
3. Has he allowed dedi servers in the menu?
4. has he disabled DLC by pressing F1 on the menu page where shows the NAT type?

I use legit MW3. All these ports are open. Dedidcated servers are allowed

Quoted from my friend

[Leonard]

2 minutes ago, Swinzon said:

I use legit MW3. All these ports are open. Dedidcated servers are allowed

Quoted from my friend

What about hitting F1 to disable  DLC on the  menu page where shows if your NAT is open?

[Swinzon]

On 22.3.2017 at 1:40 PM, Leonard said:

What about hitting F1 to disable  DLC on the  menu page where shows if your NAT is open?

Both is moderate, and both have disabled DLC, still no luck.
It`s only when trying to join party

[Leonard]

4 hours ago, Swinzon said:

Both is moderate, and both have disabled DLC, still no luck.
It`s only when trying to join party

One last thing to check for me and this one is located in your modem/router, you need to find UPnP which stands for universal plug and play. When this is enabled it fixes NAT from moderate or strict to OPEN, you need it open to join friends or for them to join you.