Be Aware of the Limit of Available VLANs on Control Switches
The limit of available VLANs on certain switch models must be considered when selecting a control switch.
The total number of VLANs required by a NETLAB+ system is calculated by taking the sum of the required VLANs for each pod, and adding 2 to that number. This total cannot exceed the available VLANs on the control switch. See the example below.
If multiple control switches are installed on a system, the number of VLANs required can not exceed the number of available VLANs on the control switch with the least number of available VLANs.
Number of VLANs Available on Each Supported Control Switch Model
| Cisco Switch Model | Minimum Required Image | Number of Available VLANs |
|---|---|---|
| Catalyst 2950-12 | 12.1(22)EA2 | 641 |
| Catalyst 2950-24 | 12.1(22)EA2 | 641 |
| Catalyst 2950C-24 | 12.1(22)EA2 | 250 |
| Catalyst 2950G-12-EI | 12.1(22)EA2 | 250 |
| Catalyst 2950G-24-EI | 12.1(22)EA2 | 250 |
| Catalyst 2950G-48-EI | 12.1(22)EA2 | 250 |
| Catalyst 2950T-24 | 12.1(22)EA2 | 250 |
| Catalyst 2960-24 | 12.2.25 | 255 |
| Catalyst 2960-48 | 12.2.25 | 255 |
| Catalyst 3550-12 | 12.1(22)EA2 | 1000 |
| Catalyst 3550-24 | 12.1(22)EA2 | 1000 |
| Catalyst 3550-48 | 12.1(22)EA2 | 1000 |
1These switches are not recommended, since the number of available VLANs is significantly less than other models.
Example of Calculating the VLANs Required for a NETLAB+ System
This example includes topologies typically used on a NETLABAE system. The total number of VLANs required for the system is calculated as shown in the table below. Keep in mind that if your NETLABPE system includes custom pods, you must include the VLANs used by those pods in your calculations.
| Topologies Installed | VLANs Required Per Pod | Number of Pods Installed | VLANs required |
|---|---|---|---|
| Multi-purpose Academy Pod | 8 | 3 | 24 |
| Network Fundamentals Pod | 10 | 1 | 10 |
| Cuatro Router Pod | 8 | 2 | 16 |
| LAN Switching Pod | 5 | 3 | 15 |
| Basic Router Pod Version 2 | 6 | 1 | 6 |
| Add 2 | 2 | ||
| Total VLANs Required | 74 |
In this example, the total number of VLANs required is 74. Therefore, switch models Catalyst 2950-12 and Catalyst 2950-24 could not be used as control switches for this system, since they provide only 64 available VLANs. Any of the other models listed in the supported control switch table, would easily satisfy the 74 VLAN requirement for this system.