database wouldn't register with the listener after ORA-600

9.2.0.4
Solaris 8

We got a ORA-00600: internal error code, arguments: [6856] at 10:15 a.m as a table was being loaded by insert into select * from; I believe the undo tablespace filled up first.
Two minutes after that the database was no longer registered with listener. It wouldn't register until rollback was completed. I'm logging a tar but anyone ever seen anything like this?

Thanks
Mike

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