Okay, this has taken me too long to not post.. So here it is..:
When your firewall is blocking SSL traffic but allowing HTTP traffic, openssl s_client will show this:
my_host:joris [/etc/stores] openssl s_client -host external_host -port 12345 CONNECTED(00000003) write:errno=104 --- no peer certificate available --- No client certificate CA names sent --- SSL handshake has read 0 bytes and written 247 bytes --- New, (NONE), Cipher is (NONE) Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE ---