Unable to connect to server

Question:
When I log into Second Life, I get to Verifying Protocol Version and stops. OR, it says it Cannot resolve domain name. OR, it says it Cannot find server someservername.lindenlab.com. What's wrong?

Answer:
This error usually means that Second Life's network connection is completely blocked by your computer or your local network setup. In the vast majority of cases, this means that a firewall (such as your router), or firewall software or internet security software, is blocking Second Life's network access. (Firewalls and internet security software frequently block most network uses that are not web browsers, instant messengers, etc.)

If you are running a firewall or firewall/internet security software, you may have to reconfigure or disable it to play Second Life.

If you are running wireless networking, you may need to use a wired connection.

If you are on a business or university internet connection, you may need to contact your network administrator to verify that you can make non-web connections to the Internet. Specifically, you need to make both UDP and TCP connections, inbound and outbound, on network ports 443 and 12020 to 13050, inclusive. If your network cannot provide the proper connection, you may be unable to connect to Second Life.

Question:
I have a firewall, or internet security software. Second Life isn't working properly, and Support thinks my firewall is to blame. Why?
Answer:
Firewalls and internet security software are designed to block network traffic! Hardware firewalls, such as routers, are typically configured to block data coming from specific network "ports" (except commonly used ones like web pages and instant messengers); this includes most network ports Second Life uses.

Internet Security software also blocks network traffic; however, these programs can cause a great deal of trouble if not configured correctly. Some versions of Internet Security software, in many popular configurations, block any non-web-browser program, often fail to notify the user of their actions, and may even block previously-listed "trusted" programs if network traffic changes, or if the executable changes (such as when a new version of Second Life is released).

If your login to Second Life fails at Verifying Protocol Version, or cannot find the server, or if you disconnect from Second Life automatically every few minutes, a firewall is typically the cause.

How your configure your home network and secure your computers is, of course, your own decision. However, Linden cannot provide support for configurations where a firewall or internet security software is interfering with Second Life's network access. These setups need to be configured properly for Second Life.

Question:
How do I configure my hardware firewall (such as a router)?
Answer:
Hardware firewalls need to allow access on certain network ports. Second Life needs to connect to ports 443/TCP, 12035/UDP, 12036/UDP, and 13000-13050/UDP. You should configure your firewall to allow outbound traffic on those ports, and related inbound traffic. You'll need to consult your firewall's documentation, or the manufacturer's website, for instructions on how to make these changes to your firewall.

Question:
How do I configure my software firewall (such as Norton Internet Security)?
Answer:
Software firewalls should have Second Life listed as a "trusted" program. Linden highly recommends turning on any notification for blocked network activity. This software should also be frequently monitored, as some versions change their own settings in an attempt to provide tighter security. You will need to consult the documentation for the software, or go to the manufacturer's website, for details on how to configure your internet security software. (Linden cannot provide support for third-party software).

Configuration for Norton products:
http://service1.symantec.com/SUPPORT/nip.nsf/docid/2002091708325336?Open&src=hot&docid=2002090915444036&nsf=nip.nsf&view=docid&dtype=&prod=Norton%20Internet%20Security&ver=2005&osv=&osv_lvl=

Question:
I've got my firewall configured properly, but I'm still having the same problems!
Answer:
Don't forget the built-in Windows Firewall; certain system updates may cause the Windows Firewall to re-enable itself. You can find the Windows Firewall in the Control Panel.
If you're using wireless networking, it may not provide a stable and fast enough connection for Second Life.