 It looks like I was being forward-thinking after all. Figure 4-6 shows conceptually how the same design would be accomplished with a Layer-3 switch. Because the switch contains the router, no external links are required. Chapter 4: VLANs With a Layer-3 switch, every port can be dedicated to devices or trunks to other switches. Port 8 Port 9 Port 10 Port 11 Port 12 Port 13 Port 14 Port 15 VLAN 20 VLAN 30 VLAN 40 VLAN 10 VLAN 10 VLAN 20 Port 0 Port 1 Port 2 Port 3 Port 4 Port 5 Port 6 Port 7 Figure 4-6. Layer-3 switch Configuring VLANs VLANs are typically configured via the CatOS or IOS command-line interpreter (CLI), like any other feature. However, some IOS models, such as the 2950 and 3550 switches, have a configurable VLAN database with its own configuration mode and commands. This can be a challenge for the uninitiated, especially because the configuration for this database is completely separate from the configuration for the rest of the switch. Even a write erase followed by a reload will not clear the VLAN database on these switches. Configuring through the VLAN database is a throwback to older models that offered no other way to manage VLANs. Luckily, all newer switches (including those with a VLAN database) offer the option of configuring the VLANs through the normal IOS CLI. Switches like the 6500, when running in native IOS mode, only support IOS com- mands for switch configuration. The Nexus line does not have a configurable VLAN database. Cisco recommends that you configure the VLAN Trunking Protocol (VTP) as a first step when configuring VLANs. This idea has merit, as trunks will not negotiate without a VTP domain. However, setting a VTP domain is not required to make VLANs function on a single switch. Configuring VTP is covered later (see Chapter 5, Trunking and Chap- ter 6, VLAN Trunking Protocol). CatOS For CatOS, create a VLAN with the set vlan command: Switch1-Catos# (enable)set vlan 10 name Lab-VLAN VTP advertisements transmitting temporarily stopped, and will resume after the command finishes