Update: There may be an issue where even with UPnP on your router working correctly, BO2 on the 4/5 isn’t actually utilizing UPnP and will still give you a moderate NAT type. All the information I said below is still correct for how BO2 should work as it did with the 360/PS3, if the developers did a proper port.

If this seems to be the case and the developers needs to fix this, then manual port forwarding is the only way. In this case, you only need to port forward UDP (not TCP) port 3074 to your PS5. Keep in mind that if your PS5 LAN IP changes (all LAN IPs provided by your router is always dynamic unless configured otherwise), then you have to update the port forwarding settings again. You can fix that by giving the Playstation a static LAN IP. Alternatively you could just live with Moderate; You just wont be able to connect with players who have strict nat type.

You do NOT need to port forward any other port but 3074 for Black Ops 2. I have tested on my side, and UDP 3074 switched me from Moderate -> Open.

Since the PS4/5 port came out, a lot of players may not understand what NAT is, or what does NAT type mean, so here's a handy guide to explain the different NAT types.

When we talk about NAT (Network Address Translation) type, we're referring to how easily other players can initiate connections to your console through your router, which is essential for P2P (Peer-to-peer) games that do not rely on a dedicated server for gameplay like modern COD games. In modern COD games, everyone connects to a dedicated server for gameplay and they all play on that server, which has its own pros and cons. Modern CoD still uses P2P connections for party chat, voice, and party joining, so NAT type still affects those, but the gameplay itself runs on a dedicated server.

The pros of a Dedicated server is that it levels the playing field when it comes to latency, which means no host advantage, and everyone's latency is more consistent. Server is also the authority on hit detection, so lag compensation works consistently. NAT Type barely matters here, and your IP is hidden from other players. In P2P, the host sees everyone's IP, which is how script kiddies were able to DDoS people in BO2 back in the 360/PS3 days. The cons is it costs the developer/publisher money, and you are at the mercy of them not shutting off the servers after 10 years or it becoming less popular and profitable (for them).

P2P on the other hand, one player is the "host" (as in, they are hosting the server for everyone), and everyone in the lobby connects to their console, which also has its own pros and cons. The pros of P2P is that it is free to operate (dedicated servers cost the publisher/developer money) and it provides low-latency for the host. But, that low latency gives the host advantage (We are talking about maybe a near 0ms in latency), and if the host leaves, the game will try to migrate by finding a new host with (ideally) an open NAT type or one that works for all the remaining players. If migration fails, the match ends prematurely and you are kicked back to lobby. The quality also depends on some random player's home upload speed (The host's connection has to upload game data to every player in the lobby simultaneously, so a weak upload chokes everyone), and on their ISP actually being competent by not being lazy or cheap with routing as some ISPs send your traffic through a distant city before it goes anywhere, which adds latency for the whole lobby.

So here is what each NAT type mean:

Open: You can connect to anyone (Open/Moderate/Strict), this is ideally the best experience. This is because you are not being double NAT’d by your ISP, and the UPnP on your router is working properly (or you manually port forwarded your PlayStation)

Moderate: You can connect to “Open” and “Moderate” players, but not strict. Slightly slower matchmaking and occasional party join failures. You may be moderate because your router isn’t properly forwarding the ports automatically with UPnP (or turned off/using the wrong type of UPnP) but your router does cone-type NAT (most consumer routers). Even with UPnP off, it can still do hole punching because of the cone-type NAT.

Strict: You can only connect to “Open” players, resulting in a poor experience. This can be caused by double NAT, CGNAT, or UPnP is off WITH the router doing symmetric NAT (some enterprise gear, some ISP gateways, certain firewall configs). Hole punching does not work with a symmetric NAT.

Some terminologies if you aren't familiar with:

UPnP: Universal plug and play. It is a feature on most routers that allows a user's device, application or game, to send a request to the router to open up a port for the outside to connect. Example: Black Ops 2 on a Playstation tells the router "I need UDP 3074 opened to 192.168.1.56". Router assigns that port, and that port is opened to the world temporary until the UPnP leasing expires, which then the device can just renew again.

CGNAT: Carrier-grade NAT, which is common on cellular networks like T-Mobile, Verizon, AT&T. This includes MVNOs and cellular home internet solutions like T-Mobile Home Internet. This is less common on terrestrial ISPs but has been growing because of IPv4 exhaustion.

Double NAT: This can happen on things like plugging in your own router into your ISP gateway, because your router is handing out local IPs to your devices, while the ISP gateway is giving your router a local IP. This prevents UPnP port forwarding working at all, and makes manual port forwarding more tedious or impossible. This can also happen with internet provided by the landlord like college dorms and apartments where the landlord has a router, and then you plug in your own router.

Hole Punching: It's the trick that lets two devices behind NAT routers connect directly to each other, even though neither can normally accept unsolicited inbound connections. Named because you're "punching a hole" through your own firewall/NAT from the inside.

Knowing what is Cone-Type NAT and Symmetric NAT isn't important, but if you have a fancy router that lets you change that setting, make sure NAT type is set to "Full Cone".

Some routers only support NAT-PMP or PCP instead of UPnP. Consoles only use UPnP (IGD), so on those routers automatic port opening won’t work at all and you’ll need to forward manually

UPnP may also been turned off by default by your router if you have never otherwise enabled it before. This is partly due to UPnP being widely regarded as a security issue and most applications have moved away from it except gaming consoles, which still rely on it, so may need to look into your router settings and look for UPnP (you might have to dig deep in the settings, sometimes the router app doesn’t even show UPnP and its buried in the classic website admin panel)

One thing I heavily advise against doing is plugging your console directly into the modem (bypassing the router). Your router has an important role as acting as your firewall to provide some protection.

Now the one reason why I dislike manual port forwarding is because if you own multiple PlayStations, only one PlayStation can use the same port at a time.

I will be updating this post as I add any information that may be important that was left out.

Issues I have seen and their potential fixes

Issue: "My NAT type changed from Open to Moderate by itself"

Possible reasons and their solutions:

1. Your UPnP lease expired or failed to renew. Rebooting the console/roles "fixes" until next time.
2. ISP-side change like a new public IP. Try restarting game, console, and if that fails router. Try it in that order.

Question: What about NAT type in PlayStation network settings?
Answer: tl;dr NAT type in this context is different from COD. If your PlayStation says NAT Type 2 (Moderate), that’s actually good. You do not want Type 3 (Strict) and you don’t really need Type 1 (Open). NAT Type 2 simply means that you are behind a firewall/NAT but your router is probably forwarding ports/UPnP is properly working. If you are strict, 99% of the time, you have a router or ISP issue. Check router first, then if that fails, check if you are being double NAT’d or CGNAT’d.

I'm finally relaunching the r/blackops2 Discord server. I'm not sure what happened to the original one as it was managed by the original moderation team, but we're back!