TNS-12541: TNS:no listener

TNS-12541: TNS:no listener

The hostname was valid but the listener was not contactable. Things to check are that the tnsnames has the correct port (and hostname) specified, and that the listener is running on the server and using the correct port.
TNS-12545: Connect failed because target host or object does not exist

The host in specified in the tnsnames is not contactable. Verify that you have spelled the host name correctly. If you have, try pinging the host with 'ping '. If ping returns 'unknown host', speak to your network admin. It might be that you have a DNS issue (you could try using the IP address if you have it to hand). If you get 'host unreachable', again speak to your network person, the problem could be down to a routing or firewall issue.

ORA-00119: invalid specification for system parameter LOCAL_LISTENER

What are the symptoms?

The local_listener parameter has been set, the listener is running, but when attempting to start the instance an ORA-00119 is reported:
SQL> startup
ORA-00119: invalid specification for system parameter LOCAL_LISTENER
ORA-00132: syntax error or unresolved network name 'LIST_ANDY'
Why is this happening?

Oracle only checks for listeners running on the default port (1521). It would have to spend all day trying every possible port number otherwise. You'll need to give it some help to find your listener.

How do I fix it?

Simply add an entry to the servers tnsnames.ora pointing at the listener. For example my listener 'LIST_ANDY' is running on port 3801, so I would add the following entry to my tnsnames:
LIST_ANDY = (ADDRESS = (PROTOCOL = TCP)(HOST = fermat)(PORT = 3801))
Test it with tnsping:
tnsping
Then try starting your instance again - it should work now.