• a 3750 can act as a layer3 switch by adding the “ip routing” command.
• It can automatically route between locally created vlans because it considers them as connected interfaces (given that the SVIs are created).
• on a device, there are 3 types of traffic: control, management, end user.
• Control traffic such as CDP, DTP, PAgP goes through vlan1 between Cisco switches, even if you clear it from trunks.
• By default, native vlan traffic is untagged. But there’s a Cisco command that tells the switch to tag all vlans.
• by default, native vlan = vlan1. If we set the native vlan to vlan100, then vlan100 frames will be untagged on trunks, and vlan1 frames will be tagged.
• SMI: Standard Multilayer Image
• EMI: Enhanced Multilayer Image
• if switch is acting L2, then we should set a Default Gateway on it to make the management vlan reachable remote ; if it is acting L3, it will have routes instead.
• switch and Management vlan
• the management IP address must be reachable from remote
• best practice: use a same subnet to manage all network devices
• on L2 SW: only one SVI is up at a time

Score is 822. Passing score was 790. It came after four days of reviewing IPv6, Route maps, BGP,… In the beginning of the test I was taking enough time to read and answer the questions. However I lost much time in my first lab simulation. The scenarion wasn’t clear to me. And each time I had to click on the console button to reach a router. And I was not seeing changes in the routing table so it confused me a lot. I began to worry about my score. And I got my second lab simulation. And immediately after, the third. I told to myself: “man, what did I do to Cisco to treat me this way?” So I had almost 38 minutes to do the third lab sim and 32 questions ! Besides, the test supervisor was tearing papers on her desk. And the other guy in the room was complaining about the bug in his exam. I was going to scream. At the end, I was almost flipping through the questions. I finished the test. The test supervisor told me “congratulations!”.