Unable to connect to other consoles (mario kart 8 deluxe)

[EpikJimmer]

So, I got the NSO free trial, bc i might buy it later on.

Aaand, the first impressions are, uhh, not so good.
Every time I try to get into a match in mario kart, it says "searching for players" for 1 minutes, then it says: Error code: 2618-0516 Unable to connect to the other consoles(s)
NAT traversal proccess has failed.

I look it up and, yeah it has to do with the NAT thing. I do a test connection on my switch and turns out i have NAT type B. Which, according to nintendo, should be fine.
I tried the DNS thing where you type 8.8.8.8 and 8.8.4.4 in primary and secondary dns respectively.

I also tried putting ip adresses gateway subnet masks and all that great stuff again, according to nintendo's website

I also tried restarting my router. Nope. Gave up for the night and slept.
And yep today still barfs me out this error.
And this only happens with mario kart; any other switch game works good online (ie. mario wonder and tetris 99)

If anyone knows what's up please let me know.
Thank you and sorry for bothering y'all.

 

[InsaneNutter]

You will need to configure your router to work with Switch online from what you have said. Mario Kart 8 is one of the more fussy games when it comes to having the router configured correctly.

First ensure UPnP is enabled on your router, that is a good starting point.

If you still get the 2618-0516 error after that then the Switch might also need a static IP on your local network. You can essentially do this as a DHCP reservation on your router (essentially the router will always give the Switch the same IP on your local network) this will then allow to setup a static port, which should resolve the 2618-0516 error.

As to how you do this on your router you will have to read the manual for the router you have.

I use pfSense for my router / firewall and this is how I fixed online play: Guide to Fix Nintendo Switch 2618-0516 Unable to Connect to others console / NAT traversal

 

[EpikJimmer]

Upnp is already enabled.
One weird thing i noticed is that my nat type is flip-flopping between B and D.
Probably has to do with that static IP thing. Gonna try this in a bit.
Thanks for your help.

Edit: It's still giving me the same error but instead of code 2618-0516 it gives me 2618-0513. Idk what this means
Edit 2: I LITERALLY DIDN'T DO ANYTHING and it suddenly worked. OK, not complaing ONE single bit. Thanks anyway!

 

[EpikJimmer]

Spoiler alert: it stopped working again. SOMEHOW.

Ik you posted a link in order to give my switch a static ip, but i have no idea how to do it on my router.
BUT I did port forward my switch aaand good news: I achieved a pure NAT type A.
Bad news: the moment i open kart 8 deluxe, it drops to D. So I probably have to do that static ip dmz thing.
I don't know anymore.

Nintendo please add normal servers to your fucking games. Thank you.

 

[EpikJimmer]

Still nope. I set up a static ip for the switch, nothing.
Still drops to D randomly.

Seriously nintendo what the fuck.