|for those who may be using the PCSX2 v1.6 with the DEV9giga-razi 1.4.0(or any version of DEV9giga-razi that I've tested) if your getting disconnections or not able to load into online games, it's because of those both it seems like. could just be the DEV9giga-razi plugin it's self. what's happening is when your using those together, you literally can't do anything else on your system. *Example* so say I'm on my PC, and connecting to MGO1(or any other online PS2 game), if i have a browser up watching movies or looking stuff up, windows update, downloading or uploading ANYTHING at ANY speeds. it won't connect to MGO1. it fails. if you have NOTHING but the MGO1 on PCSX2 1.6 then your fine. you literally can't do multiple internet bandwidth related things while trying to play online on the same device that's running PCSX2 1.6+DEV9giga-razi plugin.
i have also tested both having the WinPcap installed(this software is not updated any more) and then tried the newer Npcap. no change.
the only fix I've found is using any beta version of PCSX2 v1.7, it has the plug-ins built in but can't choose or change any kind of plugins either, except for certain versions. now the only downside is because of this, you can't play certain maps without the PCSX2 v1.7 emulator crashing/black screening. there is a fix/work around for this and i do plan on making a post to address this. but only one beta version I've found that works so far. I'll make a separate post on that. just wanting to test a couple more things before finalizing it.
supposedly the fix for this is to change the plug-in's last digit of the IP address.
thanks to "solidsnake11"