Try hamachi network turnuva26, password 123. It's a Turkish server so activity is based on time zone GMT +2:00, but it's open to players from anywhere. Usually 10 to 30 players online, depending on the time. From another post:
set it up:
Download the Hamachi LAN app:
Run it and select trial version or free version. If you use trial version, after about 25 days you can delete
\Documents and Settings\<yourname>\Application Data\Hamachi
which will cause Hamachi to issue a new ip and start a new 30 day trial period. There can only be 16 "free" users on a server, but up to 50 "trial" (or premium) users, so most are just resetting the trial version to get around the recently imposed limit of 16 "free" users.
\Program Files\EA Games\Need for Speed Underground 2\server.cfg
and delete the last line in server.cfg or put a # in front of it to remove the binding ... ADDR=%%bind("18.104.22.168") ... or download this zip with original (serverorg.cfg) and replacement file (server.cfg):
Set Hamachi network connection as highest priority (else others won't be able to see your server):
For XP/2000: Start > Control Panel > Network Connections, then, on the menu bar, click Advanced > Advanced Settings and put Hamachi at the top of the list.
For Vista: Start > Control Panel > Network and Sharing Center, then, on the left side panel, click on 'Manage Network Connections'. Now press Alt, click on Advanced > Advanced Settings and put Hamachi at the top of the list.
Start up U2 (Underground 2). If your system is multi-core, alt-ctl-del out to task manger, right click on process speed2.exe, and set affinity to only one cpu (use cpu 0 if you want to use fraps, which defaults to cpu 1), as U2 (or any NFS game before ProStreet) will crash if multiple cpus are used for U2. Back into U2, and click on LAN, hopefully you'll see one or more servers. Join that server's lobby and set the filter, the annoying aspect of U2 online because you can't set it to "any". Alt-tab out of U2 and look for messages from turnuva26, usually players will specify the filter setting just before creating a game. If you have a second monitor, you can use that to watch for filter settings.
I created a set of saves with fast cars (ecu and turbo tuning optimized via editting, and performance uniques added, so all cars are maxed out within the limits of the game. The zip includes a readme.txt which explains more: