[xcat-user] Gensshkeys bypassing user's known_hosts file

[Caruthers, Christian (LARC-E301)[SCIENCE SYSTEMS AND APPLICATIONS INC]]

Every time I log in to one of the hosts in my cluster, I see:

Warning: Permanently added 'node1' (RSA) to the list of known hosts.

Looking in my ~/ssh/config, I notice ssh is set to use /dev/null for the
UserKnownHostsFile. Looking in the gensshkeys script, I see where this is
set:

echo "ForwardX11 yes
StrictHostKeyChecking no
FallBackToRsh no
BatchMode yes
ConnectionAttempts 5
UsePrivilegedPort no
Compression no
Cipher blowfish
UserKnownHostsFile /dev/null
CheckHostIP no" >$HOMEDIR/.ssh/config

Am I missing something with ssh configuration? If I comment this line from
my .ssh/config file, I no longer get the error. Of course, if I reinstall
that node I'll get the man-in-the-middle attack warning and have to delete
the old host key from my known_hosts file. Is there some configuration I'm
missing?

Thanks
Christian