In most cases, this is because of an incorrectly configured loopback route on your system.
How to check for problems
Check if this command returns similar output:
# ping localhost PING localhost (127.0.0.1): 56 data bytes 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.3 ms 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.2 ms 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.2 ms ... |
If it doesn't, your loopback interface or route is not properly configured.
The output of the
/sbin/route |
command should contain lines like the following:
Destination Gateway Genmask Flags MSS Window Use Ifac loopback * 255.0.0.0 U 3584 0 13 lo |
The important fields are the Destination, Gateway, Genmask and Iface. This means that the system is properly configured to route all loopback traffic through the loopback interface (lo).
The output of the
/sbin/ifconfig |
command should contain the following lines:
lo Link encap:Local Loopback inet addr:127.0.0.1 Bcast:127.255.255.255 Mask:255.0.0.0 UP BROADCAST LOOPBACK RUNNING MTU:3584 Metric:1 |
This means that the loopback interface is up and running.
Your /etc/hosts file should contain the following line:
127.0.0.1 localhost |
This ensures that the "localhost" hostname is associated with your system's loopback address (127.0.0.1).
Fixing these problems
/sbin/ifconfig lo 127.0.0.1 /sbin/route add -net 127.0.0.0 |
Both these commands should, on a healthy system, be executed for you at the bootup of your computer. If this isn't happening, check your network startup files in /etc/rc.d.
If it STILL doesn't work
If none of these work, please send a full report to the KDE buglist Don't forget to mention that you have checked all these things.