BROCADE IP PRIMER

PowerPower49F Link 50F49F Link 50FConsole1 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 48ConsoleFastIron Edge X4481 3 5 7 9 1113 15 17 19 21 2325 27 29 31 33 3537 39 41 43 45 471F 2F 3F 4F2 4 6 8 10 1214 16 18 20 22 2426 28 30 32 34 3638 40 42 44 46 48Chapter 8: Virtual Local Area Network (VLAN)And now, like magic, the CFO is able to communicate with the Accountingdepartment, and all is well.VLAN 20VLAN 10taggede1-2 e125th Floor SwitchCFOtaggede1-2VLAN 20VLAN 104th Floor SwitchMarketingAccountingBut wait a minute! How do the switches know which frames are meant forVLAN 10 and which frames are meant for VLAN 20? The two-port trunk istagged. Remember those four extra bytes that are added? The frame is now alittle bit larger, but it includes, in its header, which VLAN the frame belongs to.If we were able to capture frames on the two-port trunk (either side) and lookat the VLAN ID portion of the frame (12-bit field), we would see either 00000000 1010 (in decimal, “10”) or 0000 0001 0100 (in decimal, “20”).178 Brocade IP Primer