new ccna udemy

new ccna udemy.9.2.2 Adding Control with VLANsThe problems in this section become slightly more complex, which leads to the real purpose of this section. Based on the topology used in this example, the clientis trying to communicate with another device connected to the same AP, except that this device happens to be associated with a different SSID and on a differentthe same subnet. The question is "How do I keep the two subnets separate when the AP and WLC are on a wired network? \The answer is VLAN.VLANs are a concept in switched networks that allow users to segment at the logical level. By using VLANs on the wired side of the AP and WLC, the client subnets are separated by theVLANs, the client subnets are logically segmented as if they were on the wireless space. The result is as follows.ssn > logical subnet = logical VLAN or logical broadcast domain9.2 Basic Topics 117Once the wireless frames are transmitted from the AP to the wired network, the frames must share the same physical line. You might think this is difficult because having multiple BSSIDs means having multiple networks, but it's actually not that difficult. This can be achieved by using the 802.1q protocol. 8O2.lq puts a 4-byte tag ( tag) into every 802.3 frame to indicate which VLAN the frame is a member of. If the frame from the Guest network is in VLAN 10±, the tag specifies VLAN 10, and conversely, frames from the UserNet network will be tagged with VLAN 20. Although these frames pass over the same line, they are logically segmented by different VLAN membership. The switch at either end of the "trunk link" determines which VLANO the frames belong to based on the 802.1q tag.VLAN membership mode