Why can I enter my server, but others can't?

Hi there, Internet. Recently, I've been wanting to open a Counter Strike 1.6 server [no hosting] on my computer, but I'm no informatics master. 1 year ago I was at another Internet company and everything was just fine. Now I'm at an other Internet company and stuff is messed up. They gave me a wired router. It's the SB5101E SURFboard cable modem. Internet works fine, but one day I tried to redo the 1.6 CS server, installed the plugins and everything, I logged on, but when I gave my friends the IP, not that they couldn't log on, but they couldn't even see the server [it was not responding]. OK, I tried making a Minecraft server as well, everything went ok, but other couldn't see the server, they couldn't log on. Here's the info I get when I type in ipconfig/all :
Windows IP configuration
Host name : ww
Primary Dns Suffix :
Node Type : Unknown
Ip Routing Enabled : Yes
WINS Proxy Enabled : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix :
Desription : Realtek RTL8169/8110 Family Gigabit Ethernet NIC
Physical Address : 00-1A-4D-8E-41-05
Dhpc Enabled : Yes
Autoconfiguration enabled : Yes
IP Address :
Subnet Mask :
Deafult Gateway :
DHCP Server :
DNS Servers :

This means I have a dynamic IP, right? 'Cause before I had it static.
Asked Apr 06, 2013
If you expect to pass the IP address to your friends, you must have a dedicated IP and your Internet Service Provider (ISP) may not allow that. That would explain you being able to get there (your ISP knows the real IP). Talk to tech support at your ISP.
Answered Apr 06, 2013
Edited Apr 06, 2013

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