ORA-00600 arguments: [keltnfy-ldmInit], [46], [1]

Problem Description
In oracle 10.2.0.1 while creating database with dbca it fails with message below.
ORA-00600: internal error code, arguments: [keltnfy-ldmInit], [46], [1], [], [], [], [], []

If you try to create your database manually then also the command startup nomount fails with above error message.

Cause of the Problem
In the error ldmInit indicates that the problem is related while getting host information of oracle during startup. The first argument 46 indicates the exception LDMERR_HOST_NOT_FOUND which is "gethostbyname system call fails". Oracle was unable to get host information from OS and bug fires.

Solution of the Problem
Step 01: Check permission on /etc/hosts

$ ls -l /etc/hosts
-rw-r--r--  1 root root 153 Nov 24  2007 /etc/hosts

Note that you need read permission of all users.

Step 02: Check the contents of /etc/hosts
Open the contents of /etc/hosts and check the contents inside it.
$ less /etc/hosts
Note that the contents of this files follow following format.

IP Address      fully qualified hostname    simple or short hostname     Alias

A simple example,

$ cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               database localhost.localdomain localhost

Step 03: Check the hostname and make sure you can ping your hostname.
$ hostname
database

$ ping database
PING database (127.0.0.1) 56(84) bytes of data.
64 bytes from database (127.0.0.1): icmp_seq=0 ttl=64 time=0.057 ms
64 bytes from database (127.0.0.1): icmp_seq=1 ttl=64 time=0.050 ms
64 bytes from database (127.0.0.1): icmp_seq=2 ttl=64 time=0.041 ms

If you get the following message,
$ ping database
ping: unknown host database

then possibly you will hit above bug.
And you need to modify /etc/hosts files. In the alias section you can give the name of your machine name. If your machine name is "database" you can give /etc/hosts entry as,

127.0.0.1               database localhost.localdomain localhost

And then ping database again. Make sure you are able to ping your host.

Step 04: Diagnosis DNS problem if you have DNS setup
If you have DNS setup, ping is not a tool to diagnose DNS problem. A better tool to use is nslookup, dnsquery, or dig.

$nslookup www.google.com
The forward and reverse lookup should succeed.

Step 05: Check nsswitch.conf

$ cat /etc/nsswitch.conf
hosts:      files dns

Make sure host lookup is also done through the /etc/hosts file and not just dns. The keyword files should come before dns.

Step 06: Check resolv.conf

$ cat /etc/resolv.conf
nameserver 4.2.2.2

Make sure nameserver with DNS name is added there.