Ports:
Go check out http://www.portforward.com/

Servers:
Let's look at some DALnet servers...

Hubs (you select one and it tries all servers connected to the hub):
irc.dal.net
us.dal.net
eu.dal.net

Servers (specific servers... lets you use one that you like):
jade.va.us.dal.net

To try a specific server, you first need to know what the server name is. Most networks have a website that lists all the servers. Go look for a listing. When you have one, type:

/server servername

Example:
/server jade.va.us.dal.net


Invision Support
#Invision on irc.irchighway.net