There are types of "Can't Connect" To Server Issues.
Both are easy to fix.1) The "Connection Accepted" problem - You can connect, but it just sits there and does nothing.
This is because the original Quake is not NAT fixed and if you have a router or a dsl/cable modem with router capabilities, Quake does not know how to successfully do the connection handshake.
You can easily fix this by using one of the many NAT-fixed clients:
1)
(HomePage) Modern ProQuake 3.99
2)
(HomePage) Qrack
3)
(Homepage) Historical ProQuake 3.50
(Warning: Does not have fix #2, see below!)4)
(HomePage) JoeQuake
(Warning: Does not have fix #2, see below!)5)
(HomePage) DarkPlaces
2) The "Quake won't connect at all, but my internet works" problemThis usually happens with DSL. If you have multiple IP addresses due to having DSL or a router or a 2 network cards, Quake uses the first one. With DSL, this is always an invalid IP address and many other setups may have this issue.
The following clients have the ability to properly connect under almost any network setup or combination of DSL/LAN/Router/Etc and will never have this problem.
You can, technically, fix this problem with Historical ProQuake 3.50 or JoeQuake by adding -ip x.x.x.x to your command line, but with DSL your IP address changes every time you establish a connection, so no one does this and it is a major hassle. None of the following clients need you to do that, they do it automatically.
List of clients with this fix:
1)
(HomePage) Modern ProQuake 3.99
2)
(HomePage) Qrack
5)
(HomePage) DarkPlaces
3)
Some other problemIf you are using either Modern ProQuake 3.99, Qrack 1.85 (or later) or DarkPlaces and have a connection problem, check your firewall (Norton or whatever you are using), this is almost certainly the problem. If you have seriously messed with your router settings, you might check that as well but that is very rare. Make sure you are typing the server address correctly too.