Lata, I'm guess that you're running behind a firewall and have to use a proxy to get out to the internet (big companies tend to like web logic and also have that security in place). You can change your proxy server settings (in eclipse 3.4) by selected Window > Preferences > General > Network Connections > Manual Proxy Configuration. The System Proxy Configuration didn't work for me (even though it does with most other apps). Even still I had a one or two locations that couldn't connect but most did after that change.
在Eclipse3.4版本中，選擇Window->Preferences->General -> Network Connections->Manual Proxy Configuration，設置代理如下：
摘自：http://www.coderanch.com/t/105943/vc/Weblogic-Eclipse-WTP