Switching Modes
Cisco Small Business SFE2000 and SGE2000 series switches may be used in either Layer 2 or Layer 3* modes to provide the best possible handling of traffic within your network.
* To differentiate from switches that provide a full suite of layer 3 routing capabilities, the SFE/SGE range - which only allow for static routing configurations - are often referred to as Layer 2+, rather than Layer 3 switches.
In Layer 2 mode, the switches permit traffic separation using VLANs, together with quality of service and security features based on both Layer 2 and/or Layer 3 traffic characteristics.
Layer 3 mode extends this functionality to include the routing of traffic between Layer 3 IP subnets that are configured to run within VLANs. As this routing takes place within the heart of your network, it allows you to offload this function from a router platform that would generally be placed at the network edge.
This document shows how to configure your switch for Layer 3 mode and then how to create routing policies for your network.
Please note that the following assumes that the switch is in it's factory default state.
Changing the Switch Mode of Operation
To change between Layer 2 and Layer 3 modes, you will need to access your switch using the console port at the back of the switch and the serial cable provided.
Use a console client - such as Putty - to access the Switch console. When configuring your client, use the following serial port settings:
- Port Speed: 115200 baud
- Data bits: 8
- Stop bits: 1
- Parity: None
- Flow Control: None
Once you have powered up your switch and established a console session, follow the video below to enable Layer 3 operation and assign a management IP address of 192.168.100.1 to the default VLAN interface.
Adding Additional Layer 3 Interfaces
Before continuing to the next step, you will need to manually configure the IP address of your PC Ethernet port. Use the following settings to ensure that your PC will be able to access the switch:
IP Address: 192.168.100.100
Subnet Mask: 255.255.255.0
Default Gatway: 192.168.100.1
Once your PC network interface has been configured, connect to one of the access ports and direct a web browser to the default gateway configured above.
The video below demonstrates how to access the switch web interface and create a new layer 3 interface with an IP address. Once IP traffic is being routed between layer 3 subnets by the switch, a default route is added to provide access to a remote subnet.
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A static default route could also be added to the switch to gain access to all external networks available to a site router.
Once you have finished configuring your switch, do not forget to save the settings by using the Admin File Copy menu option as illustrated below. (Copy from Running to Startup Configuration).
