C and Layer 3. You create a VLAN in CatOS, but create an SVI for the VLAN in IOS. You name the VLAN in CatOS, but add a description to the SVI in IOS. You must configure anything that is related to Layer-2 functionality in CatOS; Layer-3 and above functions must be configured in IOS. Configuring SVIs On an IOS-only switch, there is always a VLAN 1 virtual interface. This is not the case in hybrid-mode switches, because VLAN 1 does not, by default, require Layer-3 functionality. I've created two VLANs on a 6509 running in hybrid mode here: Catos-6509: (enable) sho vlan VLAN Name Status IfIndex Mod/Ports, Vlans default active 1/1-2 2/1-2 3/5-48 4/1-48 5/1-48 Lab-VLAN active VLAN0020 active 3/1-4 1002 fddi-default active 1003 token-ring-default active 1004 fddinet-default active 1005 trnet-default active The first, VLAN 10, I have named Lab-VLAN. The second, VLAN 20, has the default name of VLAN0020. To configure these VLANs in IOS, we must first connect to the MSFC using the session command. This command must be followed by the number of the module to which we'd like to connect. The number can be determined with the show module command: Catos-6509: (enable) sho mod Mod Slot Ports Module-Type Model Sub Status 1000BaseX Supervisor WS-X6K-SUP2-2GE yes ok Multilayer Switch Feature WS-F6K-MSFC2 no ok 1000BaseX Supervisor WS-X6K-SUP2-2GE yes standby Multilayer Switch Feature WS-F6K-MSFC2 no ok 10/100BaseTX Ethernet WS-X6348-RJ-45 no ok 10/100BaseTX Ethernet WS-X6348-RJ-45 no ok 10/100BaseTX Ethernet WS-X6348-RJ-45 no ok The first MSFC is reported as being in slot 15. This is normal when the supervisor is in slot 1, as the MSFC is a daughter card on the supervisor. The switch assigns an internal slot number to the MSFC. We can now connect to the MSFC: Catos-6509: (enable) session 15 Trying Router-15 Connected to Router-15. Escape character is '^]'. MSFC-6509> en MSFC-6509# Chapter 16: Multilayer Switches Another way to get to the MSFC is with the switch console command. Now that we're in IOS, let's see what the MSFC think