When I first re-installed my laptop with Fedora 8, I naturally set about installing Oracle 10g. However at the end of the dbca process, the launching of netca failed. Trying to run netca manually yielded this fun error:

[oracle ~]$ netca

Oracle Net Services Configuration:
#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
# SIGSEGV (0xb) at pc=0x004f0ab3, pid=19917, tid=3086797008
#
# Java VM: Java HotSpot(TM) Client VM (1.4.2_14-b05 mixed mode)
# Problematic frame:
# C [libc.so.6+0x6fab3] index+0x63
#
# An error report file with more information is saved as hs_err_pid19917.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
/u01/app/oracle/product/10.2.0/db_1/bin/netca: line 190: 19917 Aborted
$JRE -mx64m $SRVM_PROPERTY_DEFS -Dsun.java2d.font.DisableAlgorithmicStyles=true -classpath $CLASSPATH oracle.net.ca.NetCA $*

Well that was no good. I saw some threads with similar subject matter on the OTN forums and followed up. However time passed and then for seemingly no reason at all the next week, netca was working fine. Then a kind gentleman replied asking what my hostname was set to. BAM!

That's when it dawned on me that the hostname that I had set for this laptop was not in any DNS service available at the time. It was set up in my office in Green Bay, but I wasn't connected to that in Schaumburg. From home last night I disconnected from the VPN and removed my localhost entry for my hostname. Bingo, netca fails. Re-add the localhost entry, netca works.

I had originally added my hostname to the localhost line in /etc/hosts because gnome-terminal would take forever and day launching without DNS resolution of the hostname, waiting for the lookup to timeout. Apparently this same kind of thing is going on just to launch netca, although it just crashes.

Here is the entry in my /etc/hosts, for example:
127.0.0.1    localhost.localdomain   localhost       foo.example.com foo