The question arose when we added a second host into VLAN22. Let's call this one Host AA. It was incorrectly setup by the technician setting it up -- like this : IP: 172.20.22.16, Subnet Mask: 255.255.0.0, Gateway nothing. So the subnet mask was wrong (16 bit instead of 24) and there was no gateway address entered at all. However, Host AA was still able to connect to the webserver on Host B and load pages etc.
My question is, why was Host AA still able to connect to Host B on another subnet & VLAN even though it didn't have a gateway address? I'm guessing that the answer has something to do with the incorrect 16 Bit mask on Host AA and something related to Classless Inter-Domain routing but I'm not able to offer a great explanation.