title: Eclipse help won't show under Ubuntu
body: <p>Whenever I open some help within eclipse I get a page saying:</p>
  
  <blockquote>
    <p>Server Error. The following error occurred: [code=CANT_CONNECT_LOOPBACK] Cannot connect due to potential loopback problems</p>
  </blockquote>
  
  <p>I'm running Ubuntu 10.04.</p>
  
  <p>Any ideas what this can be?</p>
  
  <p><strong>UPDATE</strong>
  Some commands outputs (some private info replaced):</p>
  
  <pre><code>$ ifconfig -a
  eth0      Link encap:Ethernet  HWaddr 00:xx:xx:xx:xx:xx  
            inet addr:123.12.123.235  Bcast:123.12.456.255  Mask:255.255.254.0
            inet6 addr: fe80::xxx:eff:xxxx:xxxx/64 Scope:Link
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:1343040 errors:0 dropped:0 overruns:0 frame:0
            TX packets:1133672 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000 
            RX bytes:829265876 (829.2 MB)  TX bytes:242912202 (242.9 MB)
            Memory:f3200000-f3220000 
  
  lo        Link encap:Local Loopback  
            inet addr:127.0.0.1  Mask:255.0.0.0
            inet6 addr: ::1/128 Scope:Host
            UP LOOPBACK RUNNING  MTU:16436  Metric:1
            RX packets:125 errors:0 dropped:0 overruns:0 frame:0
            TX packets:125 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:0 
            RX bytes:15910 (15.9 KB)  TX bytes:15910 (15.9 KB)
  
  $ route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  123.12.123.0    0.0.0.0         255.255.254.0   U     1      0        0 eth0
  169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
  0.0.0.0         123.12.456.254  0.0.0.0         UG    0      0        0 eth0
  
  $ sudo netstat -anp
  Active Internet connections (servers and established)
  Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
  tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      765/portmap     
  tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      871/sshd        
  tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      1181/cupsd      
  tcp        0      0 0.0.0.0:52068           0.0.0.0:*               LISTEN      786/rpc.statd   
  tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      1186/mysqld     
  tcp        0      0 0.0.0.0:53709           0.0.0.0:*               LISTEN      -               
  tcp        0      0 123.12.123.235:755      123.12.5.48:2049        ESTABLISHED -               
  tcp        0      0 123.12.123.235:60793    123.12.5.129:8080       ESTABLISHED 2264/firefox-bin
  tcp        0      0 123.12.123.235:57940    123.12.5.43:8080        ESTABLISHED 2264/firefox-bin
  tcp        0      0 123.12.123.235:57928    123.12.5.43:8080        CLOSE_WAIT  2247/google-chrome
  tcp        0      0 123.12.123.235:35767    123.12.5.129:8080       ESTABLISHED 2247/google-chrome
  tcp        0      0 123.12.123.235:57930    123.12.5.43:8080        ESTABLISHED 2247/google-chrome
  tcp        0      0 123.12.123.235:57931    123.12.5.43:8080        CLOSE_WAIT  2247/google-chrome
  tcp6       0      0 :::80                   :::*                    LISTEN      1278/apache2    
  tcp6       0      0 :::22                   :::*                    LISTEN      871/sshd        
  tcp6       0      0 ::1:631                 :::*                    LISTEN      1181/cupsd      
  tcp6       0      0 :::55934                :::*                    LISTEN      1956/eclipse    
  tcp6       0      0 :::5900                 :::*                    LISTEN      1792/vino-server
  udp        0      0 0.0.0.0:35631           0.0.0.0:*                           912/avahi-daemon: r
  udp        0      0 0.0.0.0:962             0.0.0.0:*                           786/rpc.statd   
  udp        0      0 0.0.0.0:68              0.0.0.0:*                           1575/dhclient   
  udp        0      0 0.0.0.0:46149           0.0.0.0:*                           -               
  udp        0      0 0.0.0.0:5353            0.0.0.0:*                           912/avahi-daemon: r
  udp        0      0 0.0.0.0:111             0.0.0.0:*                           765/portmap     
  udp        0      0 0.0.0.0:36211           0.0.0.0:*                           786/rpc.statd   
  udp        0      0 123.12.123.235:123      0.0.0.0:*                           1689/ntpd       
  udp        0      0 127.0.0.1:123           0.0.0.0:*                           1689/ntpd       
  udp        0      0 0.0.0.0:123             0.0.0.0:*                           1689/ntpd       
  udp6       0      0 fe80::227:eff:fe07::123 :::*                                1689/ntpd       
  udp6       0      0 ::1:123                 :::*                                1689/ntpd       
  udp6       0      0 :::123                  :::*                                1689/ntpd       
  </code></pre>
  
  <p><code>Active UNIX domain sockets (servers and established)</code> due to post size limit.</p>
  
  <p><strong>UPDATE 2</strong>
  My proxy bypass settings:
  <img src="https://i.stack.imgur.com/T6dx3.png" alt="alt text"></p>