I have a quick question here would there be a problem if I assign BGP AS number 65145 on a router that already has another AS number? The 65145 I just made up which is perfectly ok right? Sorry someone has always given me a ASN this it the first time I'm making one up.
You can only run one instance of BGP on any given router.
The private AS number space is 64512 to 65535. So, in terms of selecting an AS, you're fine. In terms of configuring a second BGP AS on the router, you're not fine.