you have to change the port in the ip address. If you are joining the one where the very last 2 digits are 25 change them to 15 and if they are 15 change them to 25(I am pretty sure those are the right ones as I cant check right now correct me if I'm wrong). In console do connect, a space, and then paste the ip address and change the last two numbers.
Hopefully this helps
Edit: Downtown server ip is 94.23.19.200:27015 try that one if it doesn't work try this one 94.23.19.200:27025