A Layer 2 switch itself does not have an IP address. It works in the data link layer, mainly for MAC address learning and forwarding.
However, there will be some network devices with IP addresses on the Layer 2 switch, mainly including:
- Management interface: There will be an interface for managing the switch on the layer 2 switch, which is usually connected to the Console port or AUX port of the switch. This interface is configured with an IP address and is used to manage the switch through the network.
- Video interface: Some Layer 2 switches provide a camera interface for monitoring video through the network, and this interface will also be configured with an IP address.
- DHCP server interface: A DHCP server can be configured on some Layer 2 switches to assign IP addresses to switch ports or VLANs. The DHCP server interface has an IP address.
- SNMP agent interface: The SNMP agent service running on the Layer 2 switch is used to manage the switch through SNMP, and this service corresponds to a configured IP address.
In addition, there should be no other interfaces or services configured with IP addresses on the Layer 2 switch. The core function of a Layer 2 switch is to learn MAC addresses and forward data frames, and does not need an IP address.
Therefore, strictly speaking, a Layer 2 switch itself does not have or need an IP address. However, due to actual needs such as management and monitoring, some services and interfaces that depend on IP will run on the switch. The IP addresses configured corresponding to these services and interfaces belong to the addresses of these services, not the IP address of the switch itself.
Layer 2 switches forward data based on MAC addresses, while routers need to forward data based on IP addresses. This is why Layer 2 devices and Layer 3 devices play different roles in the network system.
In short, a Layer 2 switch does not have or need to configure an IP address, it only needs to learn and forward a MAC address. However, some management services and interfaces that require IP addresses will run on the switch. These IP addresses do not represent the addresses of the switch itself, and are only used to access these network-dependent management functions.